Cloud Engineer • Behavioral • medium

Describe a project where you proactively improved the reliability, performance, or cost-efficiency of a cloud infrastructure system without being asked.

#Initiative #Cost Optimization #Ownership

Practice

Cloud Engineer • Behavioral • medium

LinkedIn's culture values taking 'intelligent risks'. Tell me about a time you took a technical risk that failed. What did you learn, and how did you handle the aftermath?

#Risk Taking #Failure #Learning

Practice

Cloud Engineer • Behavioral • medium

Describe a time you strongly disagreed with a senior engineer or architect regarding a cloud architecture decision. How did you resolve the conflict?

#Conflict Resolution #Communication #Influence

Practice

Cloud Engineer • Behavioral • medium

You are on-call and a major production incident occurs affecting LinkedIn's core feed. Multiple alerts are firing simultaneously. How do you prioritize your actions?

#On-call #Prioritization #Communication

Practice

Cloud Engineer • Behavioral • easy

Tell me about a time you had to learn a completely new cloud technology or tool on the fly to solve a critical business problem.

#Adaptability #Continuous Learning #Problem Solving

Practice

Cloud Engineer • Coding • hard

Given a list of cloud infrastructure components and their dependencies, write a function to determine a valid deployment order. What if there is a circular dependency?

#Graphs #Topological Sort #DFS

Practice

Cloud Engineer • Coding • medium

Write a script to parse a large web server log file and return the top 10 IP addresses by request volume. How would you handle a file that is too large to fit into memory?

#Hash Map #Heap #File I/O #Python

Practice

Cloud Engineer • Coding • medium

Given a list of server downtime intervals represented as [start_time, end_time], merge all overlapping intervals to calculate the total duration the cluster was degraded.

#Arrays #Sorting #Intervals

Practice

Cloud Engineer • Coding • medium

Implement a rate limiter class that allows a maximum of N requests per minute per user. If a user exceeds the limit, return false.

#Queue #Hash Map #Concurrency

Practice

Cloud Engineer • Coding • easy

Write a function to validate if a given string representing a JSON or YAML configuration file has properly balanced and nested brackets, braces, and parentheses.

#Stack #String Manipulation

Practice

Cloud Engineer • System Design • medium

Design a distributed logging system capable of ingesting, storing, and querying petabytes of log data per day from LinkedIn's microservices.

#Logging #Kafka #Elasticsearch #Data Pipeline

Practice

Cloud Engineer • System Design • medium

Design a URL shortener service similar to LinkedIn's lnkd.in. How do you ensure uniqueness, handle high read throughput, and manage expired links?

#API Design #Database Schema #Caching #Hashing

Practice

Cloud Engineer • System Design • hard

LinkedIn is migrating a massive on-premise monolithic relational database to a distributed NoSQL database in Azure. Walk me through your migration strategy with zero downtime.

#Cloud Migration #Databases #Data Consistency

Practice

Cloud Engineer • System Design • hard

Design a system to track and process billions of 'Profile Views' per day. Users need to see an accurate count of who viewed their profile in near real-time.

#Stream Processing #Kafka #NoSQL #Aggregation

Practice

Cloud Engineer • System Design • medium

Design a scalable image processing service for LinkedIn profile pictures. It needs to handle uploads, generate multiple thumbnails, and serve them globally.

#Blob Storage #Event-Driven Architecture #CDN

Practice

Cloud Engineer • System Design • hard

Design a distributed cache system. How do you handle cache eviction, hot keys, and node failures?

#Caching #Consistent Hashing #Distributed Systems

Practice

Cloud Engineer • System Design • hard

Design a Disaster Recovery (DR) strategy for a Tier-1 LinkedIn service hosted in Azure. What are your RTO and RPO targets, and how do you achieve them?

#Disaster Recovery #High Availability #Azure

Practice

Cloud Engineer • System Design • hard

Design LinkedIn's news feed architecture. Focus on how you would generate and serve the feed to millions of concurrent users with low latency.

#Microservices #Caching #Fan-out #Databases

Practice

Cloud Engineer • System Design • hard

Design a global load balancing and traffic routing strategy for LinkedIn to ensure high availability across multiple geographic regions.

#Load Balancing #DNS #Anycast #CDN

Practice

Cloud Engineer • System Design • hard

Design an alerting and monitoring system for a cloud environment with 100,000 virtual machines. How do you handle metric aggregation and prevent alert fatigue?

#Monitoring #Time-Series Database #Distributed Systems

Practice

Cloud Engineer • Technical • medium

How do you manage Role-Based Access Control (RBAC) in Azure for a large engineering organization to enforce the principle of least privilege?

#Azure #IAM #Security

Practice

Cloud Engineer • Technical • medium

You are deploying infrastructure using Terraform, and the pipeline fails with a 'state lock' error. Walk me through how you would troubleshoot and resolve this in a production environment.

#Terraform #State Management #CI/CD

Practice

Cloud Engineer • Technical • medium

A Kubernetes pod in your production cluster is stuck in the 'Pending' state. What are the steps you would take to diagnose the root cause?

#Kubernetes #Troubleshooting #Scheduling

Practice

Cloud Engineer • Technical • medium

LinkedIn is migrating workloads to Azure. Compare Azure ExpressRoute with a Site-to-Site VPN. When would you choose one over the other for a hybrid cloud setup?

#Azure #Networking #Hybrid Cloud

Practice

Cloud Engineer • Technical • medium

You need to configure auto-scaling for an Azure Virtual Machine Scale Set (VMSS) hosting a background worker service. What metrics would you use to trigger scaling, and why?

#Azure #Auto-scaling #Metrics

Practice

Cloud Engineer • Technical • hard

You receive an alert that a Linux node has a load average of 40.0, but the CPU utilization is only 10%. What could be causing this, and how do you investigate?

#Linux #Performance Tuning #I/O

Practice

Cloud Engineer • Technical • medium

A developer reports they cannot create any new files on a Linux server, but 'df -h' shows 50% disk space available. What is the issue and how do you fix it?

#Linux #File Systems

Practice

Cloud Engineer • Technical • easy

Explain the step-by-step process of what happens at the DNS level when a user types 'www.linkedin.com' into their browser.

#DNS #TCP/IP

Practice

Cloud Engineer • Technical • medium

Design a CI/CD pipeline for a new microservice at LinkedIn. How do you ensure zero-downtime deployments and handle database schema changes?

#Jenkins/GitHub Actions #Deployment Strategies #Database Migration

Practice

Cloud Engineer • Technical • medium

How do you securely manage and inject secrets (like API keys or database passwords) into a Kubernetes-based application deployed via Terraform?

#Kubernetes #Terraform #Secret Management

Practice

Cloud Engineer • Technical • hard

LinkedIn relies heavily on Kafka. Explain how Kafka handles partition rebalancing when a new consumer joins a consumer group. What are the potential impacts on latency?

#Kafka #Messaging Queues #Concurrency

Practice

Cloud Engineer • Technical • hard

Explain how BGP (Border Gateway Protocol) works in the context of routing traffic to the nearest LinkedIn data center. What is Anycast?

#BGP #Anycast #Routing

Practice

Cloud Engineer • Technical • medium

Describe the TCP 3-way handshake. How does a SYN flood attack work, and how can we mitigate it at the infrastructure level?

#TCP/IP #DDoS Mitigation #Networking

Practice

Cloud Engineer • Technical • easy

In Kubernetes, what is the difference between a ClusterIP, NodePort, LoadBalancer, and Ingress? When would you use an Ingress over a LoadBalancer?

#Kubernetes #Networking #Services

Practice

Cloud Engineer • Technical • medium

Explain the underlying Linux technologies that make Docker containers work. How does a container differ from a virtual machine?

#Docker #Linux #Containers

Practice

Data Engineer • Behavioral • medium

Tell me about a time you took an intelligent risk in a data engineering project. What was the outcome?

#Intelligent Risks #Decision Making

Practice

Data Engineer • Behavioral • medium

Tell me about a time you disagreed with a senior engineer on the architecture of a data pipeline. How did you resolve it?

#Conflict Resolution #Relationships Matter

Practice

Data Engineer • Behavioral • medium

Tell me about a time you improved a data process or pipeline that directly benefited the end-user experience.

#Members First #Impact

Practice

Data Engineer • Behavioral • medium

Give an example of how you acted like an owner when a critical data pipeline broke over the weekend or outside of normal hours.

#Ownership #Incident Management

Practice

Data Engineer • Behavioral • medium

Tell me about a time you had to learn a new big data technology on the fly to meet a critical deadline.

#Adaptability #Demand Excellence

Practice

Data Engineer • Behavioral • medium

Describe a situation where you had to push back on a product manager or stakeholder's data request. How did you handle it?

#Communication #Open and Honest

Practice

Data Engineer • Coding • medium

Given an array of integers `nums` sorted in ascending order (with distinct values), and a target integer `target`, write a function to search `target` in `nums`. If `target` exists, then return its index. Otherwise, return -1. The array might be rotated at an unknown pivot.

#Binary Search #Arrays

Practice

Data Engineer • Coding • hard

Write a SQL query to calculate the 7-day rolling average of profile views for each user.

#Window Functions #Time Series

Practice

Data Engineer • Coding • medium

Implement an LRU (Least Recently Used) Cache. This is often used in data engineering to cache frequent database lookups.

#Data Structures #Hash Table #Linked List

Practice

Data Engineer • Coding • medium

Write a SQL query to identify the second highest salary within each engineering department at LinkedIn.

#Window Functions #Ranking

Practice

Data Engineer • Coding • medium

Given a 'connections' table and a 'messages' table, write a SQL query to find the percentage of users who connected with each other but never sent a message.

#Joins #Subqueries #Math

Practice

Data Engineer • Coding • medium

Write a SQL query to find members who applied to jobs at companies where they have at least one 1st-degree connection.

#Complex Joins #Filtering

Practice

Data Engineer • Coding • hard

You have a table of user activity logs. Write a SQL query to sessionize the data, where a new session starts if there is a gap of more than 30 minutes between activities.

#Window Functions #Sessionization #CTEs

Practice

Data Engineer • Coding • medium

Given a non-empty list of job search keywords and an integer K, return the K most frequent keywords. Sort the result by frequency from highest to lowest, and alphabetically for ties.

#Hash Table #Heap #Sorting

Practice

Data Engineer • Coding • medium

Given an array of intervals representing active user sessions on LinkedIn, merge all overlapping intervals to find the total continuous active time.

#Sorting #Arrays #Intervals

Practice

Data Engineer • Coding • medium

Write a function to find all LinkedIn connections of a specific user up to the Nth degree. You are given an API getConnections(userId) that returns a list of direct connections.

#Graphs #Breadth-First Search #Queues

Practice

Data Engineer • Coding • easy

Given an array of strings representing words and two distinct words, find the shortest distance between these two words in the list.

#Arrays #Two Pointers

Practice

Data Engineer • Coding • medium

Given a list of nested integers, return the sum of all integers in the list weighted by their depth. For example, given the list {{1,1},2,{1,1}}, return 10.

#Depth-First Search #Recursion #Arrays

Practice

Data Engineer • Coding • medium

Write a SQL query to find the top 3 job postings with the highest application rate (applications / views) in the last 7 days. Only include jobs with at least 100 views.

#Aggregations #Filtering #Sorting

Practice

Data Engineer • Coding • easy

Write a Python script to parse a large JSONL file containing LinkedIn post metadata, filter out posts with less than 10 likes, and output the result to a new file. Ensure it handles files larger than available RAM.

#Python #File I/O #Memory Management

Practice

Data Engineer • Coding • medium

Given a binary tree representing a company's organizational chart, write a function to find the lowest common manager (Lowest Common Ancestor) of two given employees.

#Trees #Recursion #Depth-First Search

Practice

Data Engineer • Coding • medium

Write a SQL query to find the cumulative sum of premium subscriptions purchased per month for the year 2023.

#Window Functions #Aggregations

Practice

Data Engineer • System Design • hard

Design a real-time dashboard for LinkedIn Job Postings analytics that allows recruiters to see how many impressions, clicks, and applies their job posts received in the last 24 hours.

#OLAP #Real-time Analytics #Kafka #Apache Pinot

Practice

Data Engineer • System Design • medium

Design a data warehouse schema for LinkedIn Learning. We need to track user video consumption, course completions, and instructor payouts.

#Dimensional Modeling #Star Schema #Data Warehousing

Practice

Data Engineer • System Design • medium

How would you design a scalable ETL pipeline to sync relational data from MySQL (e.g., user profile updates) to a data lake (Hadoop/Iceberg) for offline analytics?

#Change Data Capture #ETL #Data Lake #Apache Iceberg

Practice

Data Engineer • System Design • hard

Design a system to process and store LinkedIn Feed impressions to ensure we do not show the same post to a user more than twice in a 24-hour period.

#Caching #Bloom Filters #Stream Processing

Practice

Data Engineer • System Design • hard

Design a data pipeline to power the 'Who viewed your profile' feature. How do you handle the massive scale of profile views and ensure near real-time updates?

#Stream Processing #Kafka #Data Modeling #Scalability

Practice

Data Engineer • System Design • hard

Design a system to detect spam connection requests on LinkedIn in near real-time.

#Machine Learning Pipelines #Stream Processing #Feature Engineering

Practice

Data Engineer • Technical • medium

Explain the concept of 'Shuffle' in Apache Spark. Why is it an expensive operation and how can you minimize it?

#Apache Spark #Performance Tuning #Distributed Computing

Practice

Data Engineer • Technical • medium

How does Apache Spark achieve fault tolerance? Explain the concept of RDD lineage.

#Apache Spark #Architecture #Fault Tolerance

Practice

Data Engineer • Technical • medium

Describe the difference between a Star Schema and a Snowflake Schema. Which would you use for LinkedIn's ad campaign reporting and why?

#Data Warehousing #Schema Design

Practice

Data Engineer • Technical • medium

Explain how Kafka handles consumer offsets. What happens if a consumer fails before committing the offset?

#Apache Kafka #Fault Tolerance #Distributed Systems

Practice

Data Engineer • Technical • hard

How do you handle data skewness in a Spark join operation where one specific company ID has millions of records while others have very few?

#Apache Spark #Performance Tuning #Data Skew

Practice

Data Engineer • Technical • hard

What is Apache Iceberg and how does it solve the limitations of the traditional Hive metastore in a data lake?

#Data Lake #Apache Iceberg #Table Formats

Practice

Data Engineer • Technical • hard

You have an Airflow DAG that processes 10TB of daily log data, but it's taking too long and missing SLAs. How would you go about debugging and optimizing it?

#Apache Airflow #Performance Tuning #Troubleshooting

Practice

Data Scientist • Behavioral • medium

Tell me about a time a machine learning model or data pipeline you built failed in production. How did you handle it?

#Accountability #Problem Solving #Post-mortems

Practice

Data Scientist • Behavioral • medium

How do you communicate complex statistical concepts, like p-values or network interference, to non-technical stakeholders?

#Communication #Storytelling #Cross-functional

Practice

Data Scientist • Behavioral • medium

LinkedIn's first core value is 'Members First'. Describe a time you had to balance user experience with company revenue goals.

#Values #Decision Making #Ethics

Practice

Data Scientist • Behavioral • medium

Tell me about a time you disagreed with a Product Manager about how to interpret an experiment's results.

#Conflict Resolution #Stakeholder Management #Data Driven

Practice

Data Scientist • Behavioral • medium

Describe a time you took ownership of a vague, unstructured problem and drove it to a measurable business impact.

#Ambiguity #Initiative #Execution

Practice

Data Scientist • Coding • medium

Given a 'connection_requests' table, write a query to calculate the daily connection acceptance rate.

#Ratio Calculations #Group By #Case Statements

Practice

Data Scientist • Coding • easy

Given an array of daily active users for the past year, find the longest contiguous subarray where the DAU is strictly increasing.

#Arrays #Dynamic Programming #Python

Practice

Data Scientist • Coding • hard

Implement a K-Means clustering algorithm from scratch in Python to group similar job postings.

#Machine Learning from Scratch #Linear Algebra #Python

Practice

Data Scientist • Coding • medium

Write a Python script to parse a log file of user events and return the most frequent sequence of 3 pages visited before a job application.

#Data Manipulation #Sliding Window #Hashing

Practice

Data Scientist • Coding • medium

Given an adjacency list representing LinkedIn connections, write a function to find the shortest path (degrees of separation) between two users.

#Graphs #BFS #Python

Practice

Data Scientist • Coding • easy

Write a Python function to compute the Jaccard similarity between two users based on their listed skills.

#Python #Set Operations #Math

Practice

Data Scientist • Coding • hard

Write a SQL query to find all 2nd-degree connections for a given user ID.

#Graph Traversal in SQL #Self Joins #Filtering

Practice

Data Scientist • Coding • medium

Given a table of job applications, write a SQL query to compute the 7-day rolling average of applications per job category.

#Window Functions #Rolling Averages #Time Series

Practice

Data Scientist • Coding • medium

Write a SQL query to find the percentage of users who sent a LinkedIn message but did not receive a reply within 24 hours.

#Self Joins #Time Intervals #Left Joins

Practice

Data Scientist • Coding • medium

Write a SQL query to find the top 3 most requested skills for Data Science job postings in the last 30 days.

#Window Functions #Aggregations #Date Functions

Practice

Data Scientist • System Design • hard

Design the architecture and metrics for a real-time 'Trending News' module on the LinkedIn homepage.

#Real-time Systems #NLP #Ranking

Practice

Data Scientist • System Design • hard

How would you scale the 'People You May Know' graph algorithm to efficiently compute recommendations for 800M+ users daily?

#Big Data #Graph Processing #Scalability

Practice

Data Scientist • System Design • hard

Design an automated anomaly detection system to track and alert on data quality issues in the core user profile database.

#Data Quality #Anomaly Detection #Monitoring

Practice

Data Scientist • System Design • hard

How would you design a recommendation system for LinkedIn Learning courses?

#Recommender Systems #Collaborative Filtering #Cold Start

Practice

Data Scientist • System Design • hard

At a high level, how would you design the ranking algorithm for the LinkedIn Feed?

#Ranking #Machine Learning Architecture #Personalization

Practice

Data Scientist • System Design • hard

Design the data pipeline and telemetry required to support LinkedIn's 'Who Viewed Your Profile' feature.

#Data Engineering #Streaming #Batch Processing

Practice

Data Scientist • System Design • hard

How would you design an experimentation platform that accounts for bipartite network interference between job seekers and recruiters?

#Experimentation Architecture #Bipartite Networks #Marketplaces

Practice

Data Scientist • Technical • hard

How would you design an A/B test for a new messaging feature, considering network effects?

#Network Effects #A/B Testing #Interference

Practice

Data Scientist • Technical • medium

What features and models would you use to detect fake profiles or spam accounts on LinkedIn?

#Classification #Anomaly Detection #Feature Engineering

Practice

Data Scientist • Technical • medium

How would you build a model to predict which users are likely to churn from their LinkedIn Premium subscription?

#Churn Prediction #Survival Analysis #Classification

Practice

Data Scientist • Technical • hard

Explain how you would extract and normalize skills from a raw text resume.

#NLP #Named Entity Recognition #Embeddings

Practice

Data Scientist • Technical • hard

How would you measure the cannibalization impact of a new LinkedIn Premium tier on existing tiers?

#Cannibalization #Subscription Metrics #Revenue Modeling

Practice

Data Scientist • Technical • medium

How would you measure the success of the 'Open to Work' profile photo frame?

#Metric Design #Product Strategy #User Funnels

Practice

Data Scientist • Technical • hard

LinkedIn Feed engagement (time spent) is down 5% week-over-week, but DAU is up 2%. How would you investigate the root cause?

#Root Cause Analysis #Metric Debugging #User Segmentation

Practice

Data Scientist • Technical • medium

Design a core metric to evaluate the health of the 'People You May Know' (PYMK) feature.

#Metric Design #Network Effects #Engagement

Practice

Data Scientist • Technical • medium

How do you calculate the required sample size to detect a 1% lift in connection request acceptance rate?

#Statistical Power #Sample Size #Hypothesis Testing

Practice

Data Scientist • Technical • medium

An A/B test for a new job recommendation algorithm shows a 5% increase in applications but a 2% decrease in feed engagement. Do we launch?

#Decision Making #Trade-offs #A/B Testing

Practice

Data Scientist • Technical • medium

You run an A/B test and the p-value is 0.051. What is your recommendation to the product team?

#P-values #Statistical Significance #Decision Making

Practice

Data Scientist • Technical • medium

How do you differentiate between a novelty effect and a true behavioral change when launching a new profile layout?

#Novelty Effect #A/B Testing #Longitudinal Analysis

Practice

Data Scientist • Technical • medium

Product wants to increase the ad load in the LinkedIn feed by 10%. What metrics would you look at to evaluate the trade-offs?

#Trade-off Analysis #Monetization #User Experience

Practice

DevOps Engineer • Behavioral • medium

Tell me about a time you took an 'intelligent risk' (a LinkedIn core value) in a production environment. What was the outcome?

#Risk Management #Decision Making #LinkedIn Values

Practice

DevOps Engineer • Behavioral • medium

Tell me about a time you 'acted like an owner' (a LinkedIn core value) to resolve a critical infrastructure issue that was technically outside your direct responsibility.

#Ownership #Cross-functional Collaboration #Initiative

Practice

DevOps Engineer • Behavioral • hard

Tell me about a production outage you were involved in. What was the root cause, how did you fix it, and what was the post-mortem action item?

#Troubleshooting #Post-mortem #Continuous Improvement

Practice

DevOps Engineer • Behavioral • medium

Tell me about a time you had a disagreement with a software engineer regarding a deployment or architectural decision. How did you resolve it?

#Conflict Resolution #Communication #Collaboration

Practice

DevOps Engineer • Behavioral • easy

Tell me about a time you automated a repetitive task to improve your team's efficiency. How did you measure the impact?

#Automation #Efficiency #Impact

Practice

DevOps Engineer • Coding • medium

Write a Bash script to find and delete all .log files older than 30 days in /var/log/app, but keep the 5 most recent files regardless of age.

#Bash #Linux #Automation

Practice

DevOps Engineer • Coding • easy

Write a Python function to check if a string containing only parentheses '()', '{}', and '[]' is valid. The brackets must close in the correct order.

#Stacks #Strings

Practice

DevOps Engineer • Coding • medium

Write a Python script to parse a 50GB Nginx access log file and output the top 10 IP addresses by request count. You have limited memory.

#Python #File I/O #Data Structures #Memory Management

Practice

DevOps Engineer • Coding • medium

Write a Python script to hit a health check endpoint every 5 seconds. If it fails 3 times consecutively, send a JSON payload to a Slack webhook.

#Python #HTTP Requests #Error Handling #Automation

Practice

DevOps Engineer • Coding • medium

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals.

#Arrays #Sorting

Practice

DevOps Engineer • Coding • medium

Implement an LRU (Least Recently Used) Cache with O(1) time complexity for get and put operations.

#Data Structures #Hash Map #Doubly Linked List

Practice

DevOps Engineer • System Design • hard

Design a highly available and scalable image storage service for LinkedIn profile pictures. How do you handle caching and global distribution?

#Object Storage #CDN #Scalability #Database Design

Practice

DevOps Engineer • System Design • medium

Design a CI/CD pipeline for a new LinkedIn microservice. How would you handle automated testing, security scanning, and deployment to a Kubernetes cluster?

#Jenkins #Kubernetes #Automation #Security

Practice

DevOps Engineer • System Design • medium

Describe how you would implement auto-scaling for a stateless web application. What metrics would trigger the scaling?

#Auto-scaling #Load Balancing #Metrics

Practice

DevOps Engineer • System Design • hard

Design a distributed rate limiter for LinkedIn's public API to prevent abuse. How do you handle synchronization across multiple nodes?

#Rate Limiting #Redis #Distributed Systems #Algorithms

Practice

DevOps Engineer • System Design • hard

Design a log aggregation system capable of handling petabytes of data per day from thousands of microservices.

#Logging #Elasticsearch #Kafka #Data Pipelines

Practice

DevOps Engineer • System Design • hard

Design a monitoring and alerting system for LinkedIn's messaging service. What metrics would you track and how would you prevent alert fatigue?

#Prometheus #Grafana #SLIs/SLOs #Alerting

Practice

DevOps Engineer • System Design • hard

How would you design a highly available Kafka cluster across multiple data centers to support LinkedIn's real-time activity data?

#Kafka #Distributed Systems #High Availability #Replication

Practice

DevOps Engineer • Technical • medium

How do you manage Terraform state in a multi-developer environment? What happens if two engineers apply changes simultaneously?

#Terraform #State Management #Concurrency

Practice

DevOps Engineer • Technical • medium

Explain the TCP 3-way handshake and describe what happens when a connection enters the TIME_WAIT state. Why is TIME_WAIT necessary?

#TCP/IP #Sockets #Network Protocols

Practice

DevOps Engineer • Technical • medium

What happens exactly at the network and OS level when you type www.linkedin.com into your browser and press Enter?

#DNS #TCP/IP #TLS #HTTP

Practice

DevOps Engineer • Technical • hard

What is BGP (Border Gateway Protocol) and how does it work in the context of routing traffic to LinkedIn's global data centers?

#BGP #Routing #Internet Architecture

Practice

DevOps Engineer • Technical • medium

How do you handle secrets management (e.g., API keys, database passwords) in a CI/CD pipeline and Kubernetes environment?

#Secrets Management #HashiCorp Vault #Kubernetes Secrets #CI/CD

Practice

DevOps Engineer • Technical • easy

Explain the DNS resolution process. What is the difference between an A record, an AAAA record, and a CNAME?

#DNS #Networking Fundamentals

Practice

DevOps Engineer • Technical • hard

How do you troubleshoot a slow Kafka consumer that is lagging behind the producer? What tuning parameters would you adjust?

#Kafka #Performance Tuning #Troubleshooting

Practice

DevOps Engineer • Technical • easy

Explain the difference between a hard link and a soft (symbolic) link in Linux. What happens to each if the original file is deleted?

#Filesystems #Linux Basics

Practice

DevOps Engineer • Technical • medium

How would you secure a newly provisioned Linux server that needs to be exposed to the internet?

#Linux Security #Firewalls #SSH #Hardening

Practice

DevOps Engineer • Technical • hard

You receive an alert that a server is out of disk space. You run 'df -h' and it shows 20% free space. What is the issue and how do you fix it?

#Troubleshooting #Filesystems #Inodes

Practice

DevOps Engineer • Technical • medium

Compare and contrast Blue/Green deployments with Canary releases. When would you choose one over the other?

#Deployment Strategies #Traffic Routing #Risk Mitigation

Practice

DevOps Engineer • Technical • medium

Describe the Linux boot process step-by-step, from pressing the power button to getting the login prompt.

#OS Architecture #Boot Process #Systemd

Practice

DevOps Engineer • Technical • hard

How does Kafka handle consumer offsets, and what happens if a consumer node fails mid-processing?

#Kafka #Fault Tolerance #Message Queues

Practice

DevOps Engineer • Technical • medium

A Kubernetes pod is stuck in CrashLoopBackOff. Walk me through your exact troubleshooting steps to find the root cause.

#Kubernetes #Troubleshooting #Containers

Practice

DevOps Engineer • Technical • hard

Explain how Docker containers achieve isolation. Dive deep into Linux namespaces and cgroups.

#Docker #Linux Kernel #Namespaces #Cgroups

Practice

DevOps Engineer • Technical • medium

A developer complains their application is running slowly. How do you determine if the issue is a disk I/O bottleneck?

#Troubleshooting #Disk I/O #Performance Tuning

Practice

DevOps Engineer • Technical • medium

You receive an alert that a critical Linux server's CPU usage is at 100%. Walk me through your exact troubleshooting steps.

#Troubleshooting #Performance Tuning #CLI Tools

Practice

Frontend Engineer • Behavioral • medium

Tell me about a time you took the initiative to improve the frontend build process or developer experience on your team.

#Developer Experience #Tooling #CI/CD #Initiative

Practice

Frontend Engineer • Behavioral • hard

Tell me about a time you had to migrate a legacy system or refactor a large codebase while maintaining feature parity.

#Refactoring #Migration #Risk Management #Testing

Practice

Frontend Engineer • Behavioral • medium

Describe a time you resolved a complex bug that only occurred in the production environment.

#Debugging #Monitoring #Incident Response

Practice

Frontend Engineer • Behavioral • medium

Tell me about a time you had to push back on a product requirement because it compromised frontend performance or user experience.

#Communication #Stakeholder Management #Prioritization

Practice

Frontend Engineer • Behavioral • medium

How do you balance the need to ship features quickly versus writing perfect, maintainable code?

#Time Management #Technical Debt #Pragmatism

Practice

Frontend Engineer • Coding • hard

Build a nested comment thread component similar to the one on LinkedIn posts.

#Recursion #React #State Management #Data Normalization

Practice

Frontend Engineer • Coding • easy

Create a reusable 'Connect' button component that handles idle, loading, success, and error states.

#React #State Management #Component Design

Practice

Frontend Engineer • Coding • medium

Build a Typeahead/Autocomplete component similar to the LinkedIn search bar. It should fetch data from a mock API, display results, and handle keyboard navigation.

#React #DOM Manipulation #Debouncing #Accessibility

Practice

Frontend Engineer • Coding • medium

Implement `Promise.all()` from scratch.

#Asynchronous JavaScript #Promises #Error Handling

Practice

Frontend Engineer • Coding • medium

Write a function to flatten a deeply nested JavaScript object into a single-level object with dot-separated keys.

#Recursion #Data Structures #Object Manipulation

Practice

Frontend Engineer • Coding • medium

Implement a custom `EventEmitter` class with `on`, `off`, and `emit` methods.

#Design Patterns #Classes #Closures

Practice

Frontend Engineer • Coding • medium

Write a function to traverse a DOM tree and return an array of all text nodes.

#DOM Manipulation #Tree Traversal #Recursion

Practice

Frontend Engineer • Coding • easy

Implement a `debounce` function and explain a scenario where you would use it in the LinkedIn application.

#Closures #Timers #Performance

Practice

Frontend Engineer • Coding • medium

Implement an LRU (Least Recently Used) Cache class to store fetched user profiles.

#Data Structures #Caching #Map

Practice

Frontend Engineer • Coding • medium

Implement a function that deeply merges two JavaScript objects.

#Recursion #Object Manipulation

Practice

Frontend Engineer • Coding • easy

Write a custom React hook `usePrevious` to track the previous state of a variable.

#Hooks #useRef #useEffect

Practice

Frontend Engineer • Coding • easy

Implement `Array.prototype.reduce` from scratch.

#Arrays #Higher-Order Functions #Polyfills

Practice

Frontend Engineer • Coding • medium

Given a string of HTML, write a function to check if the tags are balanced.

#Stacks #String Parsing #Data Structures

Practice

Frontend Engineer • Coding • medium

Implement a `throttle` function.

#Closures #Timers #Performance

Practice

Frontend Engineer • Coding • easy

Write a function to convert a camelCase string to snake_case, handling edge cases like consecutive capital letters.

#String Manipulation #Regular Expressions

Practice

Frontend Engineer • Coding • medium

Create an infinite scrolling hook in React using the `IntersectionObserver` API.

#Hooks #Intersection Observer #Performance

Practice

Frontend Engineer • Coding • medium

Implement a function to find the lowest common ancestor of two nodes in a DOM tree.

#DOM Manipulation #Tree Traversal

Practice

Frontend Engineer • Coding • hard

Write a function to retry a failed network request a maximum of N times with exponential backoff.

#Asynchronous JavaScript #Promises #Error Handling #Algorithms

Practice

Frontend Engineer • System Design • hard

Design a real-time notification system for the web client.

#Real-time #Polling #WebSockets #Service Workers #Push Notifications

Practice

Frontend Engineer • System Design • hard

Design the LinkedIn Messaging Web App.

#WebSockets #Real-time #Offline Support #State Management

Practice

Frontend Engineer • System Design • medium

Design the 'People You May Know' (PYMK) carousel component.

#Component Architecture #Lazy Loading #Intersection Observer

Practice

Frontend Engineer • System Design • medium

Design the LinkedIn 'Who viewed your profile' dashboard.

#Data Visualization #Pagination #API Design #Component Architecture

Practice

Frontend Engineer • System Design • hard

Design the job application form flow, ensuring it handles offline caching and auto-saves.

#Forms #Offline Storage #IndexedDB #UX

Practice

Frontend Engineer • System Design • medium

Design a photo upload and cropping tool for the profile picture feature.

#File API #Canvas API #UX #Performance

Practice

Frontend Engineer • System Design • hard

Design the frontend architecture for the LinkedIn News Feed.

#Architecture #Performance #Virtualization #State Management #Pagination

Practice

Frontend Engineer • Technical • medium

Explain Cross-Site Scripting (XSS) and Cross-Site Request Forgery (CSRF). How do you protect a React application against them?

#Web Security #XSS #CSRF #React Security

Practice

Frontend Engineer • Technical • medium

Explain how you would ensure the LinkedIn global navigation bar is fully accessible and WCAG compliant.

#WCAG #ARIA #Keyboard Navigation #Semantic HTML

Practice

Frontend Engineer • Technical • hard

Explain how the browser rendering pipeline works, and how do you avoid layout thrashing?

#Browser Internals #DOM #CSSOM #Layout Thrashing

Practice

Frontend Engineer • Technical • medium

Compare and contrast Client-Side Rendering (CSR), Server-Side Rendering (SSR), and Static Site Generation (SSG). Which would you use for LinkedIn Jobs and why?

#Rendering Strategies #SEO #Next.js #Performance

Practice

Frontend Engineer • Technical • hard

How would you optimize the Core Web Vitals (LCP, CLS, INP) of a public LinkedIn Profile page?

#Core Web Vitals #Optimization #Rendering Strategies #Asset Loading

Practice

Full Stack Engineer • Behavioral • easy

Give an example of how you embodied the 'Members First' core value in a previous project.

#User Empathy #Product Sense #LinkedIn Values

Practice

Full Stack Engineer • Behavioral • medium

Tell me about a time you took ownership of a failing project and turned it around.

#Ownership #Leadership #Problem Solving

Practice

Full Stack Engineer • Behavioral • easy

Describe a time you received difficult feedback from a peer and how you handled it.

#Growth Mindset #Self-Awareness #Professionalism

Practice

Full Stack Engineer • Behavioral • medium

Describe a situation where you had to balance technical debt with delivering a feature quickly.

#Project Management #Trade-offs #Decision Making

Practice

Full Stack Engineer • Behavioral • medium

Tell me about a time you had to disagree with a senior engineer on a technical design.

#Conflict Resolution #Communication #Teamwork

Practice

Full Stack Engineer • Coding • medium

Implement an Event Emitter class in JavaScript to handle custom UI events on the LinkedIn feed.

#JavaScript #Design Patterns #Object Oriented Programming

Practice

Full Stack Engineer • Coding • medium

Write a function to determine if two users are exactly 3 degrees of separation apart.

#Graph #BFS #Search

Practice

Full Stack Engineer • Coding • medium

Given a matrix representing a network grid, find the number of isolated connection clusters (Number of Islands).

#Graph #DFS #BFS

Practice

Full Stack Engineer • Coding • medium

Implement Promise.all from scratch.

#JavaScript #Async #Promises

Practice

Full Stack Engineer • Coding • medium

Design and implement an LRU Cache to store recently viewed LinkedIn profiles.

#Data Structures #Linked List #Hash Map

Practice

Full Stack Engineer • Coding • hard

Given a list of connections and their skills, write an algorithm to recommend 5 new skills to a user based on what their connections have.

#Hash Map #Sorting #Recommendation Systems

Practice

Full Stack Engineer • Coding • hard

Given a stream of job postings, design a class to efficiently find the top K most frequently required skills.

#Heap #Hash Map #Streaming Data

Practice

Full Stack Engineer • Coding • medium

Given a graph of LinkedIn users, write a function to find the shortest path (degrees of separation) between two users.

#Graph #BFS #Data Structures

Practice

Full Stack Engineer • Coding • medium

Given a list of a user's job experiences represented as time intervals, merge all overlapping intervals to find their total actual time employed.

#Arrays #Sorting #Intervals

Practice

Full Stack Engineer • Coding • medium

Implement a function to render a nested comment thread on a LinkedIn post, given a flat array of comment objects with parentIds.

#JavaScript #Recursion #DOM Manipulation

Practice

Full Stack Engineer • Coding • medium

Write a function to implement a debounced search bar for the LinkedIn global search.

#JavaScript #Closures #Asynchronous Programming

Practice

Full Stack Engineer • Coding • medium

Design a React component for the LinkedIn Feed that supports infinite scrolling.

#React #Intersection Observer #Pagination

Practice

Full Stack Engineer • Coding • hard

Given a string representing a user's profile summary, write a function to justify the text (Left, Right, or Center) to fit within a specific column width.

#Strings #Formatting #Edge Cases

Practice

Full Stack Engineer • Coding • medium

Find the Lowest Common Manager (LCA) for two employees in the LinkedIn org chart.

#Trees #DFS #Recursion

Practice

Full Stack Engineer • Coding • medium

Implement a Trie data structure to support typeahead suggestions for LinkedIn connections.

#Trie #Strings #Design

Practice

Full Stack Engineer • Coding • medium

Write a function to flatten a deeply nested JSON object representing a LinkedIn user's full data export.

#Recursion #JSON #Object Manipulation

Practice

Full Stack Engineer • Coding • easy

Given an array of integers representing daily profile views, find the maximum subarray sum (highest engagement period).

#Arrays #Dynamic Programming

Practice

Full Stack Engineer • Coding • medium

Implement a function to parse a URL query string into a JavaScript object, handling arrays and encoded characters (used for job search filters).

#JavaScript #String Parsing #Web APIs

Practice

Full Stack Engineer • System Design • medium

Design a rate limiter for the LinkedIn Connections API to prevent scraping.

#Security #Distributed Systems #Algorithms

Practice

Full Stack Engineer • System Design • medium

Design the LinkedIn Endorsement system, where users can endorse connections for specific skills.

#Databases #API Design #Scalability

Practice

Full Stack Engineer • System Design • hard

Design the LinkedIn Job Search system.

#Search Engines #Elasticsearch #Microservices

Practice

Full Stack Engineer • System Design • hard

Design LinkedIn Messaging. It needs to support 1-on-1 and group chats with real-time updates.

#WebSockets #Real-time #Databases #Microservices

Practice

Full Stack Engineer • System Design • hard

Design the 'People You May Know' (PYMK) recommendation system.

#Graph Processing #Batch Processing #Machine Learning Infrastructure

Practice

Full Stack Engineer • System Design • medium

Design a system to track and display 'Who viewed your profile' in real-time.

#Stream Processing #Caching #Aggregation #Kafka

Practice

Full Stack Engineer • System Design • hard

Design the LinkedIn News Feed.

#Architecture #Scalability #Databases #Caching

Practice

Full Stack Engineer • Technical • medium

How does Kafka fit into an event-driven architecture? Give an example of how LinkedIn might use it for post engagements.

#Kafka #Distributed Systems #Messaging

Practice

Full Stack Engineer • Technical • medium

Write a SQL query to find the top 3 universities with the highest number of alumni currently working at LinkedIn.

#SQL #Aggregation #Joins

Practice

Full Stack Engineer • Technical • medium

Explain how you would handle race conditions when two recruiters try to update the same job posting simultaneously.

#Concurrency #Databases #Java

Practice

Full Stack Engineer • Technical • medium

How would you optimize the initial load time of the LinkedIn profile page?

#Performance #Front-end #Networking

Practice

Full Stack Engineer • Technical • medium

Design a database schema for LinkedIn connections, handling states like pending, accepted, and blocked.

#Schema Design #SQL #Normalization

Practice

Machine Learning Engineer • Behavioral • easy

LinkedIn's core value is 'Members First.' Tell me about a time you prioritized user experience over a short-term metric gain.

#Values #Decision Making #User Experience

Practice

Machine Learning Engineer • Behavioral • medium

What is the most challenging machine learning problem you have solved end-to-end, and what was the business impact?

#End-to-End ML #Impact #Technical Depth

Practice

Machine Learning Engineer • Behavioral • medium

Tell me about a time you disagreed with a senior engineer on an architectural or modeling decision. How did you resolve it?

#Conflict Resolution #Collaboration #Technical Debate

Practice

Machine Learning Engineer • Behavioral • easy

Describe a time you had to explain a complex machine learning concept to a non-technical stakeholder.

#Communication #Mentorship

Practice

Machine Learning Engineer • Behavioral • medium

Tell me about a time you took ownership of a failing project and turned it around.

#Ownership #Resilience #Project Management

Practice

Machine Learning Engineer • Behavioral • medium

Describe a situation where you had to debug a sudden drop in a production ML model's performance.

#Debugging #Production ML #Ownership

Practice

Machine Learning Engineer • Behavioral • medium

Tell me about a time you had to push back on a product manager's request because it would compromise model fairness or introduce bias.

#Ethics #Communication #Conflict Resolution

Practice

Machine Learning Engineer • Coding • medium

Given an integer array nums and an integer k, return the kth largest element in the array. Note that it is the kth largest element in the sorted order, not the kth distinct element.

#Array #Divide and Conquer #Sorting #Heap (Priority Queue) #Quickselect

Practice

Machine Learning Engineer • Coding • medium

Given the root of a binary tree, collect a tree's nodes as if you were doing this: Collect all the leaf nodes, remove all the leaf nodes, and repeat until the tree is empty.

#Tree #Depth-First Search #Binary Tree

Practice

Machine Learning Engineer • Coding • medium

Design a class which receives a list of words in the constructor, and implements a method that takes two words word1 and word2 and returns the shortest distance between these two words in the list. The method will be called repeatedly.

#Array #Hash Table #Two Pointers #Design

Practice

Machine Learning Engineer • Coding • easy

You have a long flowerbed in which some of the plots are planted, and some are not. However, flowers cannot be planted in adjacent plots. Given an integer array flowerbed containing 0's and 1's, and an integer n, return true if n new flowers can be planted without violating the no-adjacent-flowers rule.

#Array #Greedy

Practice

Machine Learning Engineer • Coding • medium

Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.

#Tree #Depth-First Search #Binary Tree

Practice

Machine Learning Engineer • Coding • hard

Given an array of points where points[i] = [xi, yi] represents a point on the X-Y plane, return the maximum number of points that lie on the same straight line.

#Array #Math #Geometry #Hash Table

Practice

Machine Learning Engineer • Coding • easy

Given two strings s and t, determine if they are isomorphic. Two strings s and t are isomorphic if the characters in s can be replaced to get t.

#Hash Table #String

Practice

Machine Learning Engineer • Coding • medium

Given an integer array nums, return the number of triplets chosen from the array that can make triangles if we take them as side lengths of a triangle.

#Array #Two Pointers #Sorting #Greedy

Practice

Machine Learning Engineer • Coding • medium

Given a collection of numbers, nums, that might contain duplicates, return all possible unique permutations in any order.

#Array #Backtracking

Practice

Machine Learning Engineer • Coding • hard

Design an algorithm to serialize and deserialize a binary tree. There is no restriction on how your serialization/deserialization algorithm should work.

#String #Tree #Depth-First Search #Breadth-First Search #Design

Practice

Machine Learning Engineer • System Design • medium

Design a machine learning system to detect fake profiles and spam accounts at registration.

#Anomaly Detection #Classification #Graph ML #Security

Practice

Machine Learning Engineer • System Design • hard

Design LinkedIn's 'People You May Know' (PYMK) recommendation system.

#Recommendation Systems #Graph Processing #Scalability #Machine Learning

Practice

Machine Learning Engineer • System Design • hard

Design the machine learning architecture for LinkedIn's Feed Ranking.

#Recommendation Systems #Ranking #Deep Learning #System Architecture

Practice

Machine Learning Engineer • System Design • hard

Design a Job Recommendation system that matches users to newly posted jobs.

#Recommendation Systems #Information Retrieval #NLP #Two-Tower Models

Practice

Machine Learning Engineer • System Design • hard

Design an Ad Click-Through Rate (CTR) prediction system for LinkedIn Sponsored Content.

#Ads #CTR Prediction #Imbalanced Data #Online Learning

Practice

Machine Learning Engineer • System Design • medium

Design a system to automatically extract and standardize skills from a user's unstructured profile text and resume.

#NLP #Named Entity Recognition #Knowledge Graph #LLMs

Practice

Machine Learning Engineer • System Design • medium

Design a personalized search autocomplete system for the LinkedIn search bar.

#Search #Trie #Personalization #Low Latency

Practice

Machine Learning Engineer • System Design • hard

Design a notification routing system that decides whether to send a notification via Email, Push, or In-App, and at what time.

#Reinforcement Learning #Contextual Bandits #Optimization #User Experience

Practice

Machine Learning Engineer • Technical • medium

How would you handle the cold-start problem for newly posted jobs in the Job Recommendation system?

#Cold Start #Content-Based Filtering #Exploration vs Exploitation

Practice

Machine Learning Engineer • Technical • hard

Explain how you would use Graph Neural Networks (GNNs) to generate user embeddings from LinkedIn's connection graph.

#Graph Neural Networks #Embeddings #Deep Learning

Practice

Machine Learning Engineer • Technical • medium

What offline and online evaluation metrics would you use for the LinkedIn Feed ranking model, and why?

#Metrics #A/B Testing #Ranking

Practice

Machine Learning Engineer • Technical • medium

How do you address position bias in feed ranking or search results?

#Bias Mitigation #Ranking #Causal Inference

Practice

Machine Learning Engineer • Technical • hard

Explain the difference between point-wise, pair-wise, and list-wise learning to rank. Which approach fits LinkedIn search best?

#Learning to Rank #Search #Algorithms

Practice

Machine Learning Engineer • Technical • medium

How would you design an A/B test to evaluate a new embedding model for job search? How do you handle network effects?

#A/B Testing #Experimentation #Network Effects

Practice

Machine Learning Engineer • Technical • medium

Describe how you would handle highly imbalanced data when predicting ad clicks (where CTR is typically < 1%).

#Imbalanced Data #Sampling #Loss Functions

Practice

Machine Learning Engineer • Technical • hard

How do you ensure real-time model serving latency remains under 50ms for a complex deep learning feed ranking model?

#Model Serving #Latency #Optimization #MLOps

Practice

Machine Learning Engineer • Technical • medium

What is the role of calibration in CTR prediction, and how do you calibrate a model?

#Model Calibration #Ads #Probability

Practice

Machine Learning Engineer • Technical • hard

How would you leverage Large Language Models (LLMs) to improve LinkedIn's messaging 'Smart Reply' suggestions while maintaining low latency?

#LLMs #NLP #Generative AI #Latency

Practice

Product Manager • Behavioral • medium

Tell me about a time you had to align disagreeing stakeholders on a product roadmap.

#Stakeholder Management #Conflict Resolution #Prioritization

Practice

Product Manager • Behavioral • hard

Tell me about a time you had to say no to a feature request from a major enterprise client.

#Prioritization #Client Management #Product Vision

Practice

Product Manager • Behavioral • medium

Give an example of how you embodied LinkedIn's core value of 'Members First'.

#User Empathy #Core Values #Trade-offs

Practice

Product Manager • Behavioral • hard

Tell me about a time you used data to change a deeply held assumption by leadership.

#Influence without Authority #Data-Driven Decision Making #Communication

Practice

Product Manager • Behavioral • medium

Describe a time you failed to deliver a product on time. What did you learn?

#Accountability #Project Management #Resilience

Practice

Product Manager • System Design • hard

Explain how you would design the backend architecture for LinkedIn's 'People You May Know' feature.

#Graph Databases #Scalability #Batch Processing

Practice

Product Manager • System Design • hard

Design the system architecture for LinkedIn Messaging to handle millions of concurrent users.

#Real-time Communication #WebSockets #Database Sharding

Practice

Product Manager • System Design • medium

Explain how the LinkedIn Feed ranking algorithm works at a high level to a non-technical stakeholder.

#Recommendation Systems #Communication #Algorithms

Practice

Product Manager • System Design • hard

How would you design a system to detect and remove fake profiles on LinkedIn in real-time?

#Machine Learning #Stream Processing #Trust & Safety

Practice

Product Manager • System Design • medium

How would you design an API for third-party Applicant Tracking Systems (ATS) to integrate with LinkedIn Jobs?

#API Design #B2B Integration #Security

Practice

Product Manager • Technical • hard

Should LinkedIn acquire a newsletter platform like Substack? Walk me through the strategic rationale.

#M&A #Creator Economy #Content Strategy

Practice

Product Manager • Technical • medium

How would you improve the LinkedIn Learning experience for enterprise customers?

#B2B SaaS #Enterprise Needs #Engagement

Practice

Product Manager • Technical • hard

Design a product tailored specifically for freelance workers on LinkedIn.

#Gig Economy #B2B #Payments/Invoicing

Practice

Product Manager • Technical • medium

How would you redesign the LinkedIn messaging experience to reduce spam and unwanted sales pitches?

#Trust & Safety #User Experience #Monetization Trade-offs

Practice

Product Manager • Technical • medium

Design a feature to encourage more users to endorse skills on their connections' profiles.

#Gamification #User Behavior #Data Quality

Practice

Product Manager • Technical • hard

How would you design the LinkedIn Feed experience for a brand new user with zero connections?

#Cold Start Problem #Onboarding #Content Discovery

Practice

Product Manager • Technical • hard

Design a mentorship product for LinkedIn.

#Market Expansion #User Journey #Network Effects

Practice

Product Manager • Technical • medium

How would you improve the LinkedIn Groups feature?

#User Engagement #Community Building #Product Strategy

Practice

Product Manager • Technical • medium

Design a feature to help job seekers stand out to recruiters on LinkedIn.

#User Personas #Feature Design #Talent Solutions

Practice

Product Manager • Technical • hard

Design a feature to help creators monetize their content directly on LinkedIn.

#Creator Economy #Monetization #Incentives

Practice

Product Manager • Technical • easy

How would you improve the profile creation flow to increase completion rates?

#Activation #UX/UI #Funnel Optimization

Practice

Product Manager • Technical • hard

You notice a 15% drop in connection requests sent today. How do you investigate?

#Root Cause Analysis #Metrics #Troubleshooting

Practice

Product Manager • Technical • medium

What metrics would you track to measure the success of LinkedIn Premium?

#Subscription Business #Retention #LTV/CAC

Practice

Product Manager • Technical • medium

We are launching a new 'Open to Work' profile badge. How do you set up the A/B test?

#A/B Testing #Statistical Significance #Network Effects

Practice

Product Manager • Technical • medium

Engagement on LinkedIn Polls has dropped by 10% week-over-week. What is your troubleshooting process?

#Root Cause Analysis #Engagement #Data Analysis

Practice

Product Manager • Technical • hard

How would you measure the success of the 'People You May Know' (PYMK) algorithm?

#Machine Learning #Network Growth #Success Metrics

Practice

Product Manager • Technical • hard

If you have to choose between increasing Daily Active Users (DAU) or increasing time spent per session, which do you choose and why?

#Trade-offs #Business Strategy #Engagement

Practice

Product Manager • Technical • hard

Evaluate the trade-offs of showing more ads in the LinkedIn Feed vs. showing more organic content.

#Monetization #User Experience #Trade-offs

Practice

Product Manager • Technical • medium

How do you measure the success of LinkedIn's job recommendation engine?

#Marketplace #Conversion Funnel #Machine Learning

Practice

Product Manager • Technical • hard

A new feature increases messaging volume by 5% but decreases feed scroll time by 2%. Do you launch it?

#Trade-offs #Launch Decisions #Data Interpretation

Practice

Product Manager • Technical • hard

How would you price a new tier of LinkedIn Premium targeted specifically at small business owners?

#Pricing Strategy #SMB #Monetization

Practice

Product Manager • Technical • medium

Should LinkedIn build a dating app? Why or why not?

#Brand Identity #Market Expansion #Strategic Fit

Practice

Product Manager • Technical • hard

How should LinkedIn respond to the rise of TikTok as a platform for professional networking and career advice?

#Competitive Analysis #Gen Z #Video Content

Practice

Product Manager • Technical • medium

What is the biggest threat to LinkedIn's Talent Solutions business today?

#Talent Solutions #Market Trends #Competitive Landscape

Practice

Product Manager • Technical • hard

Pitch a new monetization strategy for LinkedIn outside of Ads, Premium subscriptions, and Talent Solutions.

#Monetization #Innovation #Business Models

Practice

Software Engineer • Behavioral • medium

Tell me about a time you identified a bottleneck in a system and optimized it.

#Performance #Initiative #Impact

Practice

Software Engineer • Behavioral • medium

Tell me about a time you mentored a junior engineer or a peer who was struggling with a specific technology or codebase. How did you approach it?

#Mentorship #Teamwork #Communication

Practice

Software Engineer • Behavioral • easy

How do you prioritize your engineering tasks when you are faced with multiple urgent deadlines and shifting requirements?

#Time Management #Prioritization #Agile

Practice

Software Engineer • Behavioral • medium

Act like an owner is a core LinkedIn value. Tell me about a time you identified a critical issue in production that wasn't your responsibility, but you took ownership to resolve it.

#Ownership #Initiative #Problem Solving

Practice

Software Engineer • Behavioral • medium

Relationships matter at LinkedIn. Describe a situation where you had a strong technical disagreement with a Product Manager regarding a feature deadline. How did you resolve it?

#Conflict Resolution #Communication #Stakeholder Management

Practice

Software Engineer • Behavioral • medium

LinkedIn values taking intelligent risks. Tell me about a time you took a technical risk on a project and it failed. What did you learn?

#Risk Taking #Failure #Learning

Practice

Software Engineer • Behavioral • medium

Tell me about a time you had a disagreement with a senior engineer on a technical design. How did you resolve it?

#Conflict Resolution #Collaboration #Communication

Practice

Software Engineer • Behavioral • medium

Describe a situation where you acted like an owner to resolve a critical production issue.

#Ownership #Incident Response #Problem Solving

Practice

Software Engineer • Behavioral • medium

Tell me about a time you had to push back on a product manager's request to protect the member experience. How did you handle it?

#Communication #Prioritization #Members First

Practice

Software Engineer • Behavioral • easy

Give an example of a time you had to learn a new technology quickly to deliver a project.

#Adaptability #Learning #Execution

Practice

Software Engineer • Behavioral • medium

Describe a project that failed. What did you learn from it and how did you apply that learning later?

#Resilience #Growth Mindset #Self-Awareness

Practice

Software Engineer • Coding • easy

Design a data structure that supports the following operations: add(number) and find(value). find(value) returns true if there exists any pair of numbers whose sum is equal to the value.

#Design #Hash Table #Two Pointers

Practice

Software Engineer • Coding • hard

A transformation sequence from word beginWord to word endWord using a dictionary wordList is a sequence of words beginWord -> s1 -> s2 -> ... -> sk such that every adjacent pair of words differs by a single letter. Given two words, beginWord and endWord, and a dictionary wordList, return the number of words in the shortest transformation sequence.

#Hash Table #String #Breadth-First Search

Practice

Software Engineer • Coding • medium

Implement the RandomizedSet class: insert(val), remove(val), and getRandom(). Each function must run in average O(1) time complexity.

#Array #Hash Table #Math #Design #Randomized

Practice

Software Engineer • Coding • medium

Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value. If target is not found in the array, return [-1, -1]. You must write an algorithm with O(log n) runtime complexity.

#Array #Binary Search

Practice

Software Engineer • Coding • easy

Given an integer array nums, find the subarray with the largest sum, and return its sum.

#Array #Dynamic Programming #Divide and Conquer

Practice

Software Engineer • Coding • medium

There is an integer array nums sorted in ascending order (with distinct values). Prior to being passed to your function, nums is possibly rotated at an unknown pivot index. Given the array nums after the possible rotation and an integer target, return the index of target if it is in nums, or -1 if it is not in nums.

#Array #Binary Search

Practice

Software Engineer • Coding • easy

You have a long flowerbed in which some of the plots are planted, and some are not. However, flowers cannot be planted in adjacent plots. Given an integer array flowerbed containing 0's and 1's, and an integer n, return true if n new flowers can be planted.

#Array #Greedy

Practice

Software Engineer • Coding • medium

Given a binary tree, find the lowest common ancestor (LCA) of two given nodes in the tree.

#Tree #Depth-First Search #Binary Tree

Practice

Software Engineer • Coding • medium

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals that cover all the intervals in the input.

#Array #Sorting

Practice

Software Engineer • Coding • hard

Given an array of strings words and a width maxWidth, format the text such that each line has exactly maxWidth characters and is fully (left and right) justified.

#Array #String #Simulation

Practice

Software Engineer • Coding • hard

Given a string s, return true if s is a valid number. For example, '2', '0089', '-0.1', '+3.14', '4.', '-.9', '2e10', '-90E3', '3e+7', '+6e-1', '53.5e93', '-123.456e789' are valid.

#String #Math

Practice

Software Engineer • Coding • hard

Design an algorithm to serialize and deserialize a binary tree. There is no restriction on how your serialization/deserialization algorithm should work. You just need to ensure that a binary tree can be serialized to a string and this string can be deserialized to the original tree structure.

#Tree #Depth-First Search #Breadth-First Search #Design #String

Practice

Software Engineer • Coding • easy

Given two strings s and t, determine if they are isomorphic. Two strings s and t are isomorphic if the characters in s can be replaced to get t.

#Hash Table #String

Practice

Software Engineer • Coding • medium

Given a nested list of integers, return the sum of all integers in the list weighted by their depth. Each element is either an integer, or a list -- whose elements may also be integers or other lists. The depth is defined such that leaves have a weight of 1, and the root has the maximum weight.

#Depth-First Search #Breadth-First Search

Practice

Software Engineer • Coding • medium

Design a class which receives a list of words in the constructor, and implements a method that takes two words word1 and word2 and return the shortest distance between these two words in the list. The method will be called repeatedly.

#Array #Hash Table #Two Pointers #Design

Practice

Software Engineer • Coding • hard

Given a binary tree, design an algorithm to serialize and deserialize it.

#Tree #String #Design #DFS/BFS

Practice

Software Engineer • Coding • medium

Given an array of integers nums sorted in non-decreasing order, find the starting and ending position of a given target value.

#Binary Search #Array

Practice

Software Engineer • Coding • medium

Given a string s, return all the palindromic permutations (without duplicates) of it. Return an empty list if no palindromic permutation could be form.

#Backtracking #Hash Table #String

Practice

Software Engineer • Coding • medium

Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum and return its sum.

#Array #Dynamic Programming #Divide and Conquer

Practice

Software Engineer • Coding • medium

Evaluate the value of an arithmetic expression in Reverse Polish Notation.

#Stack #Math #Array

Practice

Software Engineer • Coding • medium

Given a nested list of integers, return the sum of all integers in the list weighted by their depth. However, the weight is defined from bottom up. (Nested List Weight Sum II)

#DFS #BFS #Math

Practice

Software Engineer • Coding • medium

Given the root of a binary tree, return the lowest common ancestor of two given nodes in the tree.

#Tree #DFS

Practice

Software Engineer • Coding • medium

There is an integer array nums sorted in ascending order (with distinct values) that is possibly rotated. Given the array nums after the possible rotation and an integer target, return the index of target if it is in nums, or -1 if it is not in nums.

#Binary Search #Array

Practice

Software Engineer • Coding • medium

Given the root of a binary tree, collect a tree's nodes as if you were doing this: Collect all the leaf nodes. Remove all the leaf nodes. Repeat until the tree is empty.

#Tree #Depth-First Search #Binary Tree

Practice

Software Engineer • Coding • medium

Given a list of intervals representing a user's work experiences (start_year, end_year), merge all overlapping experiences to find the total years of experience.

#Array #Sorting #Intervals

Practice

Software Engineer • Coding • medium

Given an integer array nums, return the number of triplets chosen from the array that can make triangles if we take them as side lengths of a triangle.

#Array #Two Pointers #Sorting #Greedy

Practice

Software Engineer • Coding • medium

Given a nested list of integers, return the sum of all integers in the list weighted by their depth. (Nested List Weight Sum)

#DFS #BFS #Array

Practice

Software Engineer • Coding • hard

Given a graph representing LinkedIn connections, write a function to find the shortest path (degrees of separation) between two members.

#Graph #BFS #Shortest Path

Practice

Software Engineer • System Design • hard

Design LinkedIn Messaging. Users should be able to send 1-on-1 messages and group messages. Messages should sync across multiple devices in real-time.

#WebSockets #Database Design #Real-time Systems

Practice

Software Engineer • System Design • medium

Design a distributed rate limiter for LinkedIn's public API.

#Algorithms #Redis #Distributed Systems #API Gateway

Practice

Software Engineer • System Design • medium

Design a Notification System for LinkedIn that handles push, email, and in-app notifications.

#Pub/Sub #Asynchronous Processing #Rate Limiting #Microservices

Practice

Software Engineer • System Design • hard

Design LinkedIn's 'People You May Know' (PYMK) recommendation system.

#Graph Databases #Batch Processing #Machine Learning Infrastructure #Hadoop/Spark

Practice

Software Engineer • System Design • medium

Design a Notification System for LinkedIn. Users can receive push notifications, emails, and in-app alerts for various events (messages, connection requests, job alerts).

#Microservices #Message Queues #Scalability

Practice

Software Engineer • System Design • medium

Design a Profile View Counter. When someone visits a LinkedIn profile, the view count should increment. The user should be able to see who viewed their profile in the last 90 days.

#Stream Processing #Database Design #Aggregation

Practice

Software Engineer • System Design • hard

Design the LinkedIn Job Search and Recommendation system. How do you ingest millions of job postings and serve relevant recommendations to users in real-time?

#Search #Machine Learning Infrastructure #Data Pipelines #Elasticsearch

Practice

Software Engineer • System Design • medium

Design a system to track and display trending hashtags on LinkedIn over the last 24 hours.

#Stream Processing #Heavy Hitters #Algorithms

Practice

Software Engineer • System Design • hard

Design a real-time messaging system (LinkedIn InMail).

#WebSockets #Chat #NoSQL #Real-time

Practice

Software Engineer • System Design • hard

Design LinkedIn's connection system. How would you efficiently store and query 1st, 2nd, and 3rd-degree connections for hundreds of millions of users?

#Graph Databases #Scalability #Data Modeling

Practice

Software Engineer • System Design • hard

Design the LinkedIn News Feed. Users should be able to see updates from their connections, companies they follow, and relevant ads. How do you handle high read/write volumes?

#Scalability #Database Design #Caching #Message Queues

Practice

Software Engineer • System Design • medium

Design a system to track and display the number of profile views a LinkedIn member gets in real-time.

#Stream Processing #Kafka #Redis #Time-series Data

Practice

Software Engineer • System Design • hard

Design a system to detect and prevent spam or abusive content in LinkedIn posts and messages.

#Machine Learning Integration #Stream Processing #Rate Limiting #Security

Practice

Software Engineer • System Design • medium

Design the LinkedIn Endorsements feature. How do you store and query who endorsed whom for what skill?

#Database Schema #High Throughput #Caching

Practice

Software Engineer • System Design • medium

Design a Distributed Rate Limiter for LinkedIn's public APIs to prevent abuse.

#Distributed Systems #Caching #Algorithms

Practice

Software Engineer • System Design • medium

Design a Typeahead Search (Autocomplete) for LinkedIn connections and global search.

#Trie #Caching #Search

Practice

Software Engineer • System Design • hard

Design the LinkedIn News Feed. How would you handle feed generation, ranking, and distribution for users with thousands of connections?

#Microservices #Caching #Fan-out #Databases

Practice

Software Engineer • System Design • medium

Design LinkedIn's Typeahead Search (Autocomplete).

#Trie #Caching #Low Latency #Data Partitioning

Practice

Software Engineer • System Design • hard

Design the LinkedIn Job Search and Application system.

#Search #ElasticSearch #Scalability #Database Consistency

Practice

Software Engineer • System Design • hard

Design a system to detect fake profiles and bot activity on LinkedIn in near real-time.

#Stream Processing #Machine Learning Infrastructure #Security

Practice

Software Engineer • Technical • easy

Implement the Singleton design pattern in a thread-safe manner. Explain the Double-Checked Locking idiom and why the 'volatile' keyword is necessary.

#Design Patterns #Multithreading #Java

Practice

Software Engineer • Technical • medium

Implement a thread-safe BlockingQueue in Java. It should support put() which blocks if the queue is full, and take() which blocks if the queue is empty.

#Java #Multithreading #Data Structures

Practice

Software Engineer • Technical • medium

Implement a Thread-Safe Bounded Blocking Queue.

#Multithreading #Locks #Condition Variables #Java

Practice

Software Engineer • Technical • medium

What happens when you type a URL into the browser? Explain the entire stack with a focus on the backend infrastructure.

#DNS #TCP/IP #Load Balancing #HTTP

Practice

Software Engineer • Technical • medium

Implement a Delayed Task Scheduler. You have a method schedule(Runnable task, long delayMs). The scheduler should execute the task after the specified delay.

#Multithreading #Heap #Design

Practice

Software Engineer • Technical • medium

Design a Retain Best Cache data structure. You are given a DataSource interface with a get(K key) method, and a Rankable interface. The cache should evict the lowest-ranked items when full.

#Caching #Heap #Hash Map #OOP

Practice

Software Engineer • Technical • medium

Explain how Apache Kafka handles message ordering and partitioning. How would you ensure strict ordering for messages related to a specific LinkedIn user?

#Kafka #Distributed Systems #Message Queues

Practice

Software Engineer • Technical • medium

Explain how Kafka partitions work and how you would handle consumer lag in a high-throughput LinkedIn service.

#Kafka #Messaging #Distributed Systems

Practice

Software Engineer • Technical • medium

Design and implement an LRU Cache that also supports a Time-To-Live (TTL) for each entry. If an entry expires, it should not be returned.

#Design #Hash Table #Linked List

Practice

LinkedIn

The Interview Loop

Recruiter Screen (30 min)

Technical Loop (3-4 Rounds)

Interview Question Bank

Describe a project where you proactively improved the reliability, performance, or cost-efficiency of a cloud infrastructure system without being asked.

LinkedIn's culture values taking 'intelligent risks'. Tell me about a time you took a technical risk that failed. What did you learn, and how did you handle the aftermath?

Describe a time you strongly disagreed with a senior engineer or architect regarding a cloud architecture decision. How did you resolve the conflict?

You are on-call and a major production incident occurs affecting LinkedIn's core feed. Multiple alerts are firing simultaneously. How do you prioritize your actions?

Tell me about a time you had to learn a completely new cloud technology or tool on the fly to solve a critical business problem.

Given a list of cloud infrastructure components and their dependencies, write a function to determine a valid deployment order. What if there is a circular dependency?

Write a script to parse a large web server log file and return the top 10 IP addresses by request volume. How would you handle a file that is too large to fit into memory?

Given a list of server downtime intervals represented as [start_time, end_time], merge all overlapping intervals to calculate the total duration the cluster was degraded.

Implement a rate limiter class that allows a maximum of N requests per minute per user. If a user exceeds the limit, return false.

Write a function to validate if a given string representing a JSON or YAML configuration file has properly balanced and nested brackets, braces, and parentheses.

Design a distributed logging system capable of ingesting, storing, and querying petabytes of log data per day from LinkedIn's microservices.

Design a URL shortener service similar to LinkedIn's lnkd.in. How do you ensure uniqueness, handle high read throughput, and manage expired links?

LinkedIn is migrating a massive on-premise monolithic relational database to a distributed NoSQL database in Azure. Walk me through your migration strategy with zero downtime.

Design a system to track and process billions of 'Profile Views' per day. Users need to see an accurate count of who viewed their profile in near real-time.

Design a scalable image processing service for LinkedIn profile pictures. It needs to handle uploads, generate multiple thumbnails, and serve them globally.

Design a distributed cache system. How do you handle cache eviction, hot keys, and node failures?

Design a Disaster Recovery (DR) strategy for a Tier-1 LinkedIn service hosted in Azure. What are your RTO and RPO targets, and how do you achieve them?

Design LinkedIn's news feed architecture. Focus on how you would generate and serve the feed to millions of concurrent users with low latency.

Design a global load balancing and traffic routing strategy for LinkedIn to ensure high availability across multiple geographic regions.

Design an alerting and monitoring system for a cloud environment with 100,000 virtual machines. How do you handle metric aggregation and prevent alert fatigue?

How do you manage Role-Based Access Control (RBAC) in Azure for a large engineering organization to enforce the principle of least privilege?

You are deploying infrastructure using Terraform, and the pipeline fails with a 'state lock' error. Walk me through how you would troubleshoot and resolve this in a production environment.

A Kubernetes pod in your production cluster is stuck in the 'Pending' state. What are the steps you would take to diagnose the root cause?

LinkedIn is migrating workloads to Azure. Compare Azure ExpressRoute with a Site-to-Site VPN. When would you choose one over the other for a hybrid cloud setup?

You need to configure auto-scaling for an Azure Virtual Machine Scale Set (VMSS) hosting a background worker service. What metrics would you use to trigger scaling, and why?

You receive an alert that a Linux node has a load average of 40.0, but the CPU utilization is only 10%. What could be causing this, and how do you investigate?

A developer reports they cannot create any new files on a Linux server, but 'df -h' shows 50% disk space available. What is the issue and how do you fix it?

Explain the step-by-step process of what happens at the DNS level when a user types 'www.linkedin.com' into their browser.

Design a CI/CD pipeline for a new microservice at LinkedIn. How do you ensure zero-downtime deployments and handle database schema changes?

How do you securely manage and inject secrets (like API keys or database passwords) into a Kubernetes-based application deployed via Terraform?

LinkedIn relies heavily on Kafka. Explain how Kafka handles partition rebalancing when a new consumer joins a consumer group. What are the potential impacts on latency?

Explain how BGP (Border Gateway Protocol) works in the context of routing traffic to the nearest LinkedIn data center. What is Anycast?

Describe the TCP 3-way handshake. How does a SYN flood attack work, and how can we mitigate it at the infrastructure level?

In Kubernetes, what is the difference between a ClusterIP, NodePort, LoadBalancer, and Ingress? When would you use an Ingress over a LoadBalancer?

Explain the underlying Linux technologies that make Docker containers work. How does a container differ from a virtual machine?

Tell me about a time you took an intelligent risk in a data engineering project. What was the outcome?

Tell me about a time you disagreed with a senior engineer on the architecture of a data pipeline. How did you resolve it?

Tell me about a time you improved a data process or pipeline that directly benefited the end-user experience.

Give an example of how you acted like an owner when a critical data pipeline broke over the weekend or outside of normal hours.

Tell me about a time you had to learn a new big data technology on the fly to meet a critical deadline.

Describe a situation where you had to push back on a product manager or stakeholder's data request. How did you handle it?

Given an array of integers `nums` sorted in ascending order (with distinct values), and a target integer `target`, write a function to search `target` in `nums`. If `target` exists, then return its index. Otherwise, return -1. The array might be rotated at an unknown pivot.

Write a SQL query to calculate the 7-day rolling average of profile views for each user.

Implement an LRU (Least Recently Used) Cache. This is often used in data engineering to cache frequent database lookups.

Write a SQL query to identify the second highest salary within each engineering department at LinkedIn.

Given a 'connections' table and a 'messages' table, write a SQL query to find the percentage of users who connected with each other but never sent a message.

Write a SQL query to find members who applied to jobs at companies where they have at least one 1st-degree connection.

You have a table of user activity logs. Write a SQL query to sessionize the data, where a new session starts if there is a gap of more than 30 minutes between activities.

Given a non-empty list of job search keywords and an integer K, return the K most frequent keywords. Sort the result by frequency from highest to lowest, and alphabetically for ties.

Given an array of intervals representing active user sessions on LinkedIn, merge all overlapping intervals to find the total continuous active time.

Write a function to find all LinkedIn connections of a specific user up to the Nth degree. You are given an API getConnections(userId) that returns a list of direct connections.

Given an array of strings representing words and two distinct words, find the shortest distance between these two words in the list.

Given a list of nested integers, return the sum of all integers in the list weighted by their depth. For example, given the list {{1,1},2,{1,1}}, return 10.

Write a SQL query to find the top 3 job postings with the highest application rate (applications / views) in the last 7 days. Only include jobs with at least 100 views.

Write a Python script to parse a large JSONL file containing LinkedIn post metadata, filter out posts with less than 10 likes, and output the result to a new file. Ensure it handles files larger than available RAM.

Given a binary tree representing a company's organizational chart, write a function to find the lowest common manager (Lowest Common Ancestor) of two given employees.

Write a SQL query to find the cumulative sum of premium subscriptions purchased per month for the year 2023.

Design a real-time dashboard for LinkedIn Job Postings analytics that allows recruiters to see how many impressions, clicks, and applies their job posts received in the last 24 hours.

Design a data warehouse schema for LinkedIn Learning. We need to track user video consumption, course completions, and instructor payouts.

How would you design a scalable ETL pipeline to sync relational data from MySQL (e.g., user profile updates) to a data lake (Hadoop/Iceberg) for offline analytics?

Design a system to process and store LinkedIn Feed impressions to ensure we do not show the same post to a user more than twice in a 24-hour period.

Design a data pipeline to power the 'Who viewed your profile' feature. How do you handle the massive scale of profile views and ensure near real-time updates?

Design a system to detect spam connection requests on LinkedIn in near real-time.

Explain the concept of 'Shuffle' in Apache Spark. Why is it an expensive operation and how can you minimize it?

How does Apache Spark achieve fault tolerance? Explain the concept of RDD lineage.

Describe the difference between a Star Schema and a Snowflake Schema. Which would you use for LinkedIn's ad campaign reporting and why?

Explain how Kafka handles consumer offsets. What happens if a consumer fails before committing the offset?

How do you handle data skewness in a Spark join operation where one specific company ID has millions of records while others have very few?

What is Apache Iceberg and how does it solve the limitations of the traditional Hive metastore in a data lake?

You have an Airflow DAG that processes 10TB of daily log data, but it's taking too long and missing SLAs. How would you go about debugging and optimizing it?

Tell me about a time a machine learning model or data pipeline you built failed in production. How did you handle it?

How do you communicate complex statistical concepts, like p-values or network interference, to non-technical stakeholders?

LinkedIn's first core value is 'Members First'. Describe a time you had to balance user experience with company revenue goals.

Tell me about a time you disagreed with a Product Manager about how to interpret an experiment's results.

Describe a time you took ownership of a vague, unstructured problem and drove it to a measurable business impact.