SDE2 Interview Questions at Flipkart

Design Flipkart's flash sale system. The system must handle 1M concurrent users trying to buy a limited inventory of 10K items without overselling. Walk through the inventory locking, queueing, and database isolation strategy.

You need to implement infinite scroll in React. The list fetches 20 items per page. Users scroll down, new items load. When they scroll back up, previously loaded items should still be there. How do you implement this correctly?

Design Flipkart's product search and ranking system. A user searches "wireless earphones under 2000". How do you retrieve, rank, and filter 10,000+ matching products in under 200ms?

Design Flipkart's order management system. From "Place Order" to "Delivered", walk through every state transition, the microservices involved, how you handle partial failures (payment succeeds but inventory deduct fails), and eventual consistency.

Design a coupon/discount system for Flipkart Big Billion Days. The system must validate, apply, and prevent double-use of millions of coupons with high concurrency. Cover idempotency and distributed locking.

Describe a time you had to convince a skeptical stakeholder to adopt a technical solution. What data or arguments did you use and what was the outcome?

What is a race condition in Java, and how does synchronized prevent it? Show a minimal example of a non-thread-safe counter and the fix.