Databricks

Databricks

Unified analytics platform built on Apache Spark for data engineering and ML.

4 Rounds ~21 Days Hard
Start Mock Interview

The Interview Loop

Recruiter Screen (30 min)

Standard fit check, behavioral questions, and resume overview.

Technical Loop (3-4 Rounds)

Deep dive into domain knowledge, coding, and system design.

Interview Question Bank

Data Scientist Behavioral medium

Databricks moves very fast. Tell me about a time you had to deliver an ML model or analysis under a very tight deadline with ambiguous requirements.

#Ambiguity #Delivery #Prioritization #Bias for Action
Data Scientist Behavioral easy

Tell me about a time you discovered a significant flaw in your data or model after it was already shared with stakeholders. How did you handle it?

#Integrity #Communication #Problem Solving #Ownership
Data Scientist Coding medium

Write a PySpark script to calculate the 7-day rolling average of cluster compute costs per customer, given a massive dataframe of daily billing events.

#PySpark #Window Functions #Distributed Computing
Data Scientist Coding medium

Given a table of `job_runs` (job_id, workspace_id, start_time, end_time, status), write a SQL query to find the workspace with the highest rate of failed jobs in the last 7 days, considering only workspaces with at least 100 runs.

#SQL #Aggregations #CTEs #Filtering
Data Scientist Coding medium

Given a list of strings representing Databricks notebook execution logs, write a Python function to extract the most frequent error codes and return them sorted by frequency. Assume logs are unstructured text.

#Python #String Parsing #Hash Maps #Regex
Data Scientist Coding hard

Given a table of `user_logins` (user_id, login_timestamp), write a SQL query to find the maximum number of consecutive days each user has logged into the Databricks platform.

#SQL #Window Functions #Gaps and Islands
Data Scientist Coding hard

Write a Python algorithm to implement a stratified sampling method for a dataset that is too large to fit into memory, reading it chunk by chunk.

#Python #Streaming #Reservoir Sampling #Memory Management
Data Scientist System Design hard

Design a machine learning system to predict which Databricks customers are likely to churn in the next 30 days. Discuss feature engineering, model selection, and how you would scale the inference using Delta Lake.

#Churn Prediction #Delta Lake #Scalability #Feature Engineering
Data Scientist System Design hard

Design an LLM-powered coding assistant for Databricks notebooks (similar to Databricks Assistant). Focus on the telemetry data you would collect to evaluate the model's performance offline and online.

#LLMs #Telemetry #Online Evaluation #Product Analytics
Data Scientist Technical hard

Explain how Apache Spark handles out-of-memory (OOM) errors during a wide transformation. How would you diagnose and fix an OOM error in a PySpark ML pipeline?

#Apache Spark #OOM #Debugging #Distributed ML
Data Scientist Technical medium

How does Delta Lake handle ACID transactions under the hood? Explain how you would use time travel to recover a dropped ML feature table.

#Delta Lake #ACID #Time Travel #Storage
Data Scientist Technical hard

You are training a distributed XGBoost model on a massive dataset using Spark. The training job is taking too long and some executors are idling. How do you identify the bottleneck and optimize the training process?

#Distributed ML #XGBoost #Spark #Performance Tuning
Data Scientist Technical medium

We want to test a new auto-scaling algorithm for Databricks SQL warehouses. How would you design the A/B test? What are your primary and secondary metrics?

#A/B Testing #Experimentation #Metrics #Cloud Infrastructure
Data Scientist Technical medium

Explain the difference between a broadcast hash join and a sort-merge join in Spark. When would you force a broadcast join in a data science pipeline?

#Spark Joins #Optimization #Big Data #Query Planning
Data Scientist Technical medium

How would you use MLflow to manage the lifecycle of a model that requires frequent retraining? Describe the architecture of your CI/CD pipeline for this model.

#MLflow #Model Registry #CI/CD #Model Lifecycle

Difficulty Radar

Based on recent AI-sourced data.

Meet Your Interviewers

The "Standard" Interviewer

Senior Engineer

Focuses on core competencies, system constraints, and clear communication.

Simulate

Unwritten Rules

Think Out Loud

Always explain your thought process before writing code or drawing architecture.

Practice Now