Technical Lead at PhonePe

How it went

What they would tell you

How to prepare

Their background

Round by round

1. 1

   DSA60 min

   I applied for the Technical Lead role at PhonePe through a referral. The process started with an initial call from HR, then I had two technical interviews and one system design interview. Each round was an elimination round. Technical Questions: Trap Rain Water

   • I was able to discuss the approach for solving the problem efficiently. Although the implementation took longer than expected, I was able to explain the two-pointer approach and its time complexity.

   • The interviewer asked for the code, but due to time constraints, we skipped the implementation part. Left View of a Binary Tree

   • I quickly explained the logic for level order traversal using BFS, the interviewer seemed satisfied with the explanation Behavioural Questions:

   • A situation where I improved response time and system efficiency

   • A time when I was recognized for my work by leadership or peers

   • Trapping Rainwater
   • Left View of a Binary Tree
2. 2

   Core Theory + System design60 min

   Mix of Java and Spring Boot questions, followed by a System Design The questions were focused on testing my theoretical knowledge and practical application in real scenarios Java Basics:

   • Collections Framework: Asked about HashMap, TreeMap, and their use cases.

   • Tricky Output Questions: I was given several snippets of code involving overriding, static, try/finally, and multiple inheritance in Java and asked to predict the output. Spring Boot:

   • Questions related to dependency injection, REST APIs, and service layering in Spring Boot. System Design: Design a View Count and Like Count System:

   • I was asked to design a backend system to track view counts and like counts for videos.

   • I explained how to maintain real-time counts using caching (e.g., Redis), followed by persistent storage in a database like PostgreSQL.

   • The system needed to handle high scalability and low latency for large-scale video platforms. How Video Streaming Systems Work:

   • The interviewer asked about how video streaming systems work and how they handle quality switching during playback.

3. 3

   Final Discussion60 min

   Mostly behavioural and my previous projects and how I handled different work scenarios Questions like: Tell me about a time when you led a project Tell me about a situation where you faced a technical challenge

What came up