I had interviewed with Flipkart for SDE-3 position.
A recruiter from staffing agency had reached out to me with this opportunity. The overall process was as follows:
Round 1 - Machine Coding
I was briefed about a project, which had to do with Covid Vaccination Management kind of system.
I was expected to design and code the solution with the APIs they had mentioned, taking into consideration all the features. It was a pretty lengthy problem statement, which required handling concurrent requests, starvation and a lot more.
I was expected to write the complete solution in 150 mins while presenting my screen and the session was being recorded.
There were no restrictions as such on the language (I had chosen Java), but they were looking for good demoable code, while checking OOPS concepts, designing.
After 150 mins, I had to present/explain my code to panelists and zip and share the same with them. They also asked questions around it.
Round 2 - PS/DS
In this round, they had shared a google doc with me for writing the code. They had asked a difficult question (at least for me) which was something like - "Minimum time required to propagate the information from root to all child nodes of n-ary tree where in one path, the information can only be propagated at one level and other levels will need to wait". I was not able to write the complete code, but was able to explain my approach and was able to write the code for main logic. Approx time: 90 mins
Round 3 - Design
In this round, I was grilled a lot on Rate limiting as I had mentioned that on my resume. They asked me to design a rate limiter with and without redis cache (both HLD and LLD). Optimize my approach. I was also asked to write the logic for working of sliding window rate limiter. This round lasted for over 90 mins.
Round 4 - HM
This round was majorly around my resume. The projects that I had worked on. My strengths and weaknesses. Again some discussions around rate limiter, making it configurable, other approaches to have rate limiter like behaviour. Reason for switching. My expectations from the role. Few scenario based questions like conflict with manager, team member. This round lasted for little over 75 mins.
4 days after this, I received a call from staffing agency that they have got the news that I have been shortlisted. The same was confirmed by Flipkart recruiter after another 2 days.
I hope this helps someone to prepare well.