SDE-3 at J.P. Morgan

How it went

What they would tell you

How to prepare

Their background

Round by round

1. 1

   System Design Round60 min

   In system design round, Interviewer asked to design an airline reservation system, discussion began with high-level architecture, including how bookings, cancellations, and seat allocations would flow. I then moved into Low-Level Design, drawing class diagrams and discussing how entities like Flights, Passengers, Tickets, and Seats interact.The interviewer also asked a few medium-level technical questions.

2. 2

   DSA Round60 min

   In this round, I had a coding problem based on trees. The interviewer asked me to find the Lowest Common Ancestor (LCA) of two nodes in a binary tree. I started by explaining the first approach: a simple recursive method. I told him how we search for both nodes in the left and right subtrees, and when both sides return a value, that’s when we know we’ve found the LCA. It’s straightforward and uses backtracking naturally. Then I explained the second approach, which is faster when you have to answer many LCA queries. In this method, we store the parent pointer for every node. Later, we move up from one node and store all its ancestors, then move up from the other node until we find the first common one. After explaining both methods, I wrote clean code for the recursive approach.

   • Lowest Common Ancestor of a Binary Tree IV
3. 3

   Managerial round60 min

   This round felt more like a conversation than an interview. The interviewer mainly wanted to understand how I work with people. They asked me how I handle conflicts with teammates, and I explained that I try to listen, stay calm, and find a solution that works for everyone. We also talked a lot about my past projects, what decisions I made, why I made them, and what responsibilities I took on.

What came up