My interview process started in March, where I was invited for OA. Which I completed but after that there was no communication, my initial thought was that I might have not cleared the OA that's why there is no responce.
But Fast forward to July 2020, I got a call from Amazon Recuriter again where we had a very good discussion again and for some reason March OA results were not announced. But I was invited for the first Interview round which is Phone Screening

Round 0 - Phone Screen

Question 1. Solution for a logger method which can save the logs for an APP which has 1K T/S.
Question 2. Delete the leaf node fo BST
Question 3. Convert the BST TO Dobule LL.
Question 4. Some LP

Again there was complete silence and I thought I have not cleared this round. But to my surprise got the call from the recuiter informing that I have cleared the phone screen round they want to proceed further.

Round 1 - System Design + LP

Question 1. Vending Maching class diagram (UML) - object oriented design
This round took me by suprise I was hoping to High Level System Design quesitons in this round. But I still tried to completed the design I kept having the discussion with the interviewer and kept explaining the process.
Question 2. Some LP such as didn't agree with your peer and risk you took

Round 2 - Coding round

Question 1. Zoombie problem. Matrix with 0 & 1. How much time it would take to convert all the humans to zoombie.
Initially it took time to understand the problem but I kep discussion the solution with the interviewer and then I coded the complete solution.

Round 3 - Coding round

Question 1. I don't remeber the exact question. but it was related to the N balls with W weight
Question 2. Find the president problem
I kept having the discussion with the interviewer in both the problems. For the first problem I provided the solution then we started going for the optimised solution. for the second problem we only had the discussion as we're running out to time.

Round 4 - System Design + LP

Question 1. Design Chess class digram (UML) - Object Oriented Design.
Again I was expecting some HLD question for which I was prepared well enough.
Question 2. Some LP

After some time I received email that they have decided not to more forward, at this time.
Hope this helps someone.

Thanks to everyone for sharing there experiences and creating a strong community.