Deloitte

Multinational professional services network with offices in over 150 countries.

4 Rounds ~21 Days Medium

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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

All Roles Backend Engineer 35 Cloud Engineer 35 Data Engineer 35 Data Scientist 35 DevOps Engineer 35 Frontend Engineer 35 Full Stack Engineer 35 Machine Learning Engineer 35 Product Manager 35 Software Engineer 35

All Topics Algorithms 8 System Design 5 Time Management 2 Backend 2 Security 2 Database 2 Frontend 2 Communication 1

Full Stack Engineer • Behavioral • medium

Tell me about a time you had to push back on a client's technical request because it wasn't feasible or secure.

#Communication #Consulting #Conflict Resolution

Practice

Full Stack Engineer • Behavioral • easy

Describe a situation where you had to learn a new technology or framework very quickly to deliver a project.

#Learning #Agile #Problem Solving

Practice

Full Stack Engineer • Behavioral • medium

How do you handle disagreements with a senior developer or technical architect regarding a design decision?

#Conflict Resolution #Communication #Collaboration

Practice

Full Stack Engineer • Behavioral • medium

Explain a complex technical concept (like microservices or API gateways) to a non-technical business stakeholder.

#Stakeholder Management #Consulting #Empathy

Practice

Full Stack Engineer • Behavioral • medium

Tell me about a time a deployment failed in production. What was your role, and how did you handle it?

#Incident Management #Accountability #DevOps

Practice

Full Stack Engineer • Behavioral • medium

How do you balance the desire to write perfect, refactored code with the need to meet tight client deadlines?

#Prioritization #Agile #Pragmatism

Practice

Full Stack Engineer • Behavioral • easy

Describe your experience working in Agile/Scrum environments. How do you ensure you are contributing effectively to sprint goals?

#Agile #Scrum #Teamwork

Practice

Full Stack Engineer • Behavioral • medium

Tell me about a time you identified a security vulnerability or critical bug in your team's code during a code review.

#Code Review #Security #Proactive

Practice

Full Stack Engineer • Behavioral • medium

As a consultant, you may be assigned to multiple deliverables. How do you prioritize your tasks when everything seems urgent?

#Prioritization #Consulting #Organization

Practice

Full Stack Engineer • Behavioral • easy

Why do you want to work at Deloitte, and what draws you to technology consulting specifically?

#Motivation #Consulting #Career Goals

Practice

Full Stack Engineer • Coding • easy

Given an array of integers nums and an integer target, return indices of the two numbers such that they add up to target.

#Arrays #Hash Map

Practice

Full Stack Engineer • Coding • easy

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

#Stacks #Strings

Practice

Full Stack Engineer • Coding • medium

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals.

#Arrays #Sorting

Practice

Full Stack Engineer • Coding • medium

Design a data structure that follows the constraints of a Least Recently Used (LRU) cache.

#Hash Map #Doubly Linked List #Design

Practice

Full Stack Engineer • Coding • medium

Given an array of strings, group the anagrams together. You can return the answer in any order.

#Strings #Hash Map #Sorting

Practice

Full Stack Engineer • Coding • medium

Given a string s, find the length of the longest substring without repeating characters.

#Sliding Window #Hash Set #Strings

Practice

Full Stack Engineer • Coding • medium

Given an integer array nums and an integer k, return the k most frequent elements.

#Heaps #Hash Map #Bucket Sort

Practice

Full Stack Engineer • Coding • easy

Given the head of a singly linked list, reverse the list, and return the reversed list.

#Linked List #Pointers

Practice

Full Stack Engineer • System Design • hard

Design a scalable e-commerce checkout system that handles high traffic during events like Black Friday.

#Scalability #Payments #Microservices #Message Queues

Practice

Full Stack Engineer • System Design • medium

Design a URL shortener service like Bitly.

#Hashing #Database #Caching #Load Balancing

Practice

Full Stack Engineer • System Design • hard

Design a secure document management system for a federal government client.

#Security #RBAC #Blob Storage #Compliance

Practice

Full Stack Engineer • System Design • medium

Design a real-time chat application like Microsoft Teams or Slack.

#WebSockets #Real-time #Database #Pub/Sub

Practice

Full Stack Engineer • System Design • hard

How would you approach migrating a legacy monolithic application to a microservices architecture for a large financial client?

#Microservices #Migration #Strangler Pattern #Enterprise Architecture

Practice

Full Stack Engineer • Technical • medium

How does the Event Loop work in Node.js, and how does it handle asynchronous operations?

#Node.js #Asynchronous Programming #Architecture

Practice

Full Stack Engineer • Technical • easy

Explain the difference between React Hooks and Class Components. Why did React introduce Hooks?

#React #JavaScript #Architecture

Practice

Full Stack Engineer • Technical • medium

Explain Dependency Injection in Spring Boot. What are the different ways to inject dependencies?

#Java #Spring Boot #Design Patterns

Practice

Full Stack Engineer • Technical • medium

Compare REST and GraphQL. When would you choose one over the other for a client project?

#REST #GraphQL #Network

Practice

Full Stack Engineer • Technical • easy

What are the primary differences between SQL and NoSQL databases? How do you decide which to use?

#SQL #NoSQL #Data Modeling

Practice

Full Stack Engineer • Technical • medium

Explain the JWT (JSON Web Token) authentication flow in a full-stack application.

#Authentication #JWT #Web Security

Practice

Full Stack Engineer • Technical • medium

How do microservices communicate with each other? What are the pros and cons of synchronous vs asynchronous communication?

#Microservices #REST #Message Queues #gRPC

Practice

Full Stack Engineer • Technical • medium

What strategies would you use to optimize the performance of a large-scale React application?

#React #Performance #Optimization

Practice

Full Stack Engineer • Technical • easy

What are ACID properties in a database system? Can you explain each one?

#SQL #Transactions #Database Theory

Practice

Full Stack Engineer • Technical • medium

Walk me through how you would Dockerize a full-stack application (e.g., Node.js backend, React frontend, Postgres DB).

#Docker #Containers #CI/CD

Practice

Full Stack Engineer • Technical • easy

What is CORS, why does it exist, and how do you configure a backend to handle it properly?

#CORS #Security #HTTP

Practice

Full Stack Engineer • Technical • easy

Explain the difference between Promises and Async/Await in JavaScript. How do you handle errors in both?

#JavaScript #Asynchronous

Practice

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The "Standard" Interviewer

Senior Engineer

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

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Unwritten Rules

Think Out Loud

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

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