Background:

5+ YoE working @ investment bank
Round 1: LLD Round (Interviewvector)

Ques: Design Online book reader (Kindle)
Covered all FR, NFR, Classes, DB schema, API Design and Design Patterns

Interview experience: Panel was easy going, asked some good questions, I was able to answer all
Feedback: Positive

Round 2: HLD Round (Interviewvector)

Ques: Design Streaming service similar to Twitch
Discussed about FR, NFR, Estimation, High level Microservice, Database architecture

Interview experience: Panel was bad at communication but we managed. I was able to answer all follow up questions/deep dives.
Feedback: Positive

Round 3: HLD Round (Zepto EM)

Ques: Design Inventory Management System (for say KFC/McD)
Discussed about FR, NFR, Estimation, Core API's, High level Microservice, Database architecture

Interview experience: Good panel, asked some questions on concurrency, transactions & locks. Did some deep dive on MongoDB internal working. He was looking for specific jargons.
Feedback: Positive

Round 4: Hiring Manager Round (Zepto head of eng)

1. LLD for WeWork (Only database schema)
2. HLD of a project you worked on last 6 months
3. Questions on Apache Kafka (current cluster is handling 10m requests per second, how do you scale to 1B)
4. Questions on Postgres (internal workings)
5. Languages worked with?
6. Tell me about a time when a project you worked on went wrong
7. Tell me about a time you had to give someone a critical feedback
8. How do you make sure you write quality code
9. Tell me about a time you learnt something outside of job
10. Two things you love and hate about your current job

Interview experience: Panel was arrogant and unresponsive so it was hard to have a two way communication. He was nodding his head at times so I had to be happy with that. Interview went well, answered everything, yet got rejected.
Feedback: Rejected