My years of experience : 1 year 6 months.

** Round 1 : Online coding assessment**
Returning sum of Happy Numbers in a given range and other question was easy which I dont remember.

Verdict : Selected

** Round 2 : Online DSA round**

a. Count of subarrays with zero sum .
Interviewer was very helpful. I committed some mistake in forming logic but he provided me edge case and that's when I realized the fault. He provided some hints and I was able to form the correct logic.

b. No of ways to reach the top of stair if given the number of steps in a stair and a person can either climb by one step or two steps . ( Standard DP problem)
I knew the approach so I explained from basic recursive approach , its time complexity and then I showed him overlapping subproblems which can be optimzed using Memoization. I also showed him Bottom top approach and further optimized it to using constant space .

Verdict : Selected

Round 3 :Coding and REST API Design round
A coding snippet was provided which was a method in java.
I was asked to provide review comments on the code like in terms of any error, any areas of improvement.
I mentioned some comments regarding naming conventions of the variables, suggested some exception handling strategies and use of Optional to mitigate the NullPointer Exception occurence.

Then interviewer asked to design the Rest APIs of a problem and asked to discuss how would you design backend and which data base you would choose and reason for that.
It was a simple problem .
In a notepad I metioned the rest-apis ( endpoints,expected request ,expected response for each endpoint) and answered further questions about design.

Verdict : Selected

Round 4 : HM round with Engineering Lead
Behavioural questions were asked to ensure if the candidate fits culturally and behaviourally in the organization eg . What keeps you motivated ? , What is the size of your team and do you think large team size is a challenge ? , How you keep yourself updated with latest tech ? ..etc

Verdict : Selected.

That's it .