Hello! this was my experience being interviewed by Phonepe for their SDE-Tools for network infrastructure role .

Status: Fresher (Graduating in 2023) | Tier 2 College in India
Experience: 6 month internship at my own college IT department
Date: July 2022

I didnt find any interview experiences for the SDE tools role so i felt i'd give my experience here

The interview process followed the following

1: Coding Round :
They held the coding round on their DoSelect Test platform.
3 questions were asked. two were on dynamic programming and one was mathematics and string formatting. i was able to answer all 3 and hence proceeded to the next round

2: Technical Interview 1 (50 minutes):
A member of the Tools team interviewed me. They explained what the team does and then asked me to solve a question similar to this one
https://leetcode.com/problems/factorial-trailing-zeroes/
I was able to give a naive solution initially and then suggested ways i could do it in logarithmic time. They were satisfied with my answer and
then went on to ask me about my Internship which was pretty application focused, how i could improve on what i did and what would i do better next time and so on.
Since i code primarily in python, i was then asked questions on python and how python loads files when we use open().Then i was asked about decorators and how to implement one in python.
Then i was asked about virtual memory, database theorems like CAP and ACID and Caching mechanism and how would i code a naive caching method (also how would something like python's lru_cache do it)
then i was asked about the linux commands i know. i was then asked how to use grep to query a string in a file.

3 : Technical Interview 2 (30 minutes)
The manager of the tools team then interviewed me. I was the last person to be interviewed in this round, so it was a bit laid back and relaxed.
First, i was asked about what i think was the future of technology and some thoughts on various fields like machine learning, networking like 5g and cloud computing. I was then asked various questions on computer networking concepts like proxy servers, ipv4 and ipv6, what is utf8 and the need for something like it, How content is distributed accross a network (like netflix), difference between hashing and encryption and so on.
I was also asked about blockchain, mutex vs semaphores and some various other tech related questions and how much of a hold i have on them.

Note that i did answer most of these, but it was mostly surface level. the intent of these questions was mostly to see if i had an awareness in these topics, and to what extent.

Result : They offered me an internship for my final year.

My takeaway is that many of these questions, while they do seem very alien and vague, they do make sense for the role they are offering, which involved working on the core networking infrastructure of phonepe.

Suggestions :

• Be ready for anything. I didnt expect to be asked about 5g or regular expressions. I personally thought i would be asked more dsa questions
• Maintain an interest or knowhow on what is happening in the tech industry. Although it is not for everyone, this is a huge plus for many interviews.
• Confidence is key. If you dont know something, say it with confidence, and tell what you do know