Paytm Senior Technical Lead | Reject

I recently interviewed at Paytm for the Senior Technical Lead role. Sharing my Round 1 experience for those preparing for similar senior-level interviews.

Round 1 – DSA + Behavioural

This round focused on a combination of data structures/algorithms and behavioural evaluation.

DSA Questions:

The interviewer first asked about my proficiency level in DSA, and based on that, started with the Trap Rain Water problem.

I was able to come up with a working solution after some discussion. The interviewer asked me to code it, but since the implementation was taking longer than expected, we skipped the full code and moved on.

The next problem was Left View of a Binary Tree.

I was able to explain the logic quickly and successfully implemented the code during the interview.

Behavioural Questions:

The second half of the round focused on behavioural questions using the STAR format.

Key questions included:

• A situation where I worked on improving response time and system efficiency significantly.
• A project or moment where I was regarded exceptionally well by peers or leadership.

This round was designed to assess both problem-solving ability and leadership mindset — crucial for any senior-level engineering role

Round 2 - Technical cum System Design

After introduction started with general Java questions (Collections framework) and tricky output based questions. Asked some questions related to overriding, static, try, finally, multiple inheritance.

Then asked some questions related to Spring Boot.

Then asked to design the system for view count and like count of videos.

Also asked about how the video streaming system works, how streaming switches to low video quality.