Flipkart Senior Software Engineer Interview Experience (2026)

Round 1 – DSA + Coding (90 Minutes)

The first round consisted of two coding problems on an online coding platform. The focus was on writing optimized solutions and explaining the approach.

Questions:

• Given an array of integers, find the longest subarray with sum equal to K.
• Design an LRU Cache supporting O(1) get() and put() operations.

Follow-up Discussion:

• Time and space complexity analysis.
• Edge cases and scalability.
• How would the solution behave for very large datasets?

Topics Covered:

• HashMap
• Sliding Window
• Linked List
• Design Problems

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Round 2 – Java, Spring Boot & MongoDB (75 Minutes)

This round focused on backend development and framework knowledge.

Java

• Difference between HashMap and ConcurrentHashMap.
• How does JVM memory management work?
• Explain volatile, synchronized, and ReentrantLock.
• Java 8 Stream API questions.
• Garbage Collection basics.

Spring Boot

• Bean lifecycle.
• Dependency Injection.
• Spring Boot Auto Configuration.
• REST API exception handling.
• Transaction Management.
• Microservices communication.

MongoDB

• Indexes and compound indexes.
• Aggregation Pipeline.
• Embedding vs Referencing.
• Sharding basics.
• Why choose MongoDB over a relational database?

A small coding task was also given to design a REST API for Product Inventory with CRUD operations.

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Round 3 – System Design (90 Minutes)

The interviewer asked me to design a Product Recommendation Service similar to Flipkart.

Discussion included:

• High-level architecture.
• API Design.
• Database selection.
• Cache using Redis.
• Handling millions of requests.
• Horizontal scaling.
• Load Balancer.
• Message Queue for asynchronous processing.
• Logging and Monitoring.
• Failure handling.

The interviewer continuously asked follow-up questions about scaling, bottlenecks, and improving latency.

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Round 4 – Hiring Manager + CS Fundamentals (60 Minutes)

The discussion started with my previous projects and the technical challenges I had solved.

CS Fundamentals

• Process vs Thread.
• Deadlock conditions.
• Virtual Memory.
• Database Normalization.
• ACID properties.
• CAP Theorem.
• Indexing vs Partitioning.
• SQL vs NoSQL.
• REST vs gRPC.

Behavioral questions included:

• Tell me about a production issue you resolved.
• A time when you disagreed with your team.
• How do you review code?
• How do you mentor junior engineers?

The interviewer also discussed my current responsibilities, architecture decisions, and ownership of production systems.

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Result

Selected.

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Preparation Tips

• Practice medium-level DSA problems focusing on HashMap, Trees, Graphs, and Dynamic Programming.
• Be comfortable with Java multithreading, collections, and JVM internals.
• Revise Spring Boot concepts such as Dependency Injection, Transactions, Security, and REST API best practices.
• Learn MongoDB indexing, aggregation, and schema design.
• Prepare one end-to-end system design (URL Shortener, Product Catalog, Notification Service, etc.).
• Revise Operating Systems, DBMS, Networking, and OOP concepts.
• Be ready to discuss projects in depth, including architecture decisions and performance optimizations.