Education: BTech from Tier-1 College in India
Position: SDE2 at Amazon (2.5 yrs)
Location: Bengaluru
Total YOE: 7.5 yrs

Round-1 (Machine Coding): 

Design a PhonePe Resolution Service.

A scenario like there are tickets/issues and there are agents and application 
will either assign the ticket to an agent or it will be added to the backlog of an agent. 
For matching a ticket with the appropriate agent, 
the application can consider the ticket-type and match it with an agent with that speciality.
If no agent with that speciality is found, the ticket can be assigned to any agent or its backlog.

Experience: Had 2.5 hrs to code it on my personal IDE and then send it back to the recruiter over email (after zipping it).
The code was fairly straightforward and be sure to use strategy pattern for the ticket assignment process, 
so that the assignment logic is pluggable. 
All in-memory data structures were used.

[Word of caution]: Time Management!!

Evaluation of the round happened a couple of days later. It was a 30-min discussion 
where I had to discuss about the code and explain the design and implementation choices.

Round-2 (PS/DS):

1. Find an element in a rotated sorted array.
2. Given a binary tree, where each node is storing a value, 
   find the maximum path sum of any non-empty path. 
   [Similar question: https://leetcode.com/problems/binary-tree-maximum-path-sum

Round-3 (System Design):

Design a Tagging Service. Similar to the Atlassian Interview Design question.

Had to come up with:
- API(s)
- Overall Architecture
- Database Design choices
- Leaderboard update for the trending tags. <<Hourly Dashboard, Weekly Dashboard>>

For the leaderboard part, you can refer to this article that I found helpful: 
https://medium.com/@satyajitganguly.techie/system-design-interview-a-cycling-tracker-app-b3f78e07688c

Round-4 (Hiring Manager):

General Discussion about my past work, my areas of interest, critical contributions. 
It went very smooth and the manager was focused on explaining me 
the work at PhonePe and the team structure. 
The manager explained about the critical projects that are currently going on 
and the different technologies that they work on. 
All the backend services are built in-house (like distributed-job-scheduler, 
event-ingestion-service, metrics-aggregation-service, object-storage-service etc). 

Recruiter came back after a couple of days and said that they were inclined to make an offer. 
The offer discussion happened a week later over a virtual meeting with the hiring manager.
The joining date was also discussed over this call.
It took a week more for the final offer to come via email.