Hi LeetCoders, you can read my interview experience with PayU for the role of SDE 2 - Backend. There were 3 rounds in total.

Round 1 (Virtual):
Q1. Detect cycle in a linked list.
A1. Solved using slow-fast pointers.

Q2. Two sum problem.
A2. Solved using hashmap.

Q3. Design a generic user schema in SQL.
A3. Designed a basic schema and had a little discussion over how to store profile picture (DB vs S3).

Difficulty: Super Easy

Round 2 (Virtual)
High level design of Instagarm

• Started with functional and non-functional requirements, then actors and their actions.
• Mentioned all entities needed and moved to schema design, but the interviewer interrupted the flow.
• Discussion started on data ingestion and data retrieval. How to build user feed? How to serve meantime incoming posts? How to handle celebrities' posts? Push vs pull models.
• Brief discussion happened on the ranking of posts in a user feed.
• At last, discussion shifted to scaling, rate-limiting, and efficient storage of media files.

Difficulty: Easy, because the intervewer kept hopping on different topics but never drilled down one single topic.

Round 3 (F2F)
It was Hiring Manager round. Initial discussion mostly revolved around my work experience. Tried gauging do I know what I do from a business perspective. Later, questions were asked on logging, monitoring, and alerting.

Questions to be mentioned:

• Does Kafka support idempotency?
• Does Kafka guarantee ordering of events?
• There's a GET API fetching users' data, consumed by millions of clients. API response varies client-to-client and clients can also demand alteration in their response. How would you cater?

Difficulty: Medium

Final Result: Selected

~Anonymous