The interview process was slow. For 5 rounds, it took approximately 1.5 months. In the end, the HR did not even give any feedback nor tell me the outcome of the process.

Round 1:

Q1) How to add time taken by an endpoint without adding calculation logic in every controller method?

Q2) What is the N+1 problem in Hibernate? How is it resolved?

Q3) 1 coding question: https://www.geeksforgeeks.org/find-maximum-meetings-in-one-room/

Q4) Design a YouTube.

Round 3:

Q1) Count the number of occurrences (or frequency) of a number in a sorted array. Solution: https://www.geeksforgeeks.org/count-number-of-occurrences-or-frequency-in-a-sorted-array/

Q2) Design a TinyURL System.

Round 5:

This was an offline round. 3 questions were shared via email and solutions had to be reverted.

1. Algo question:

• N people, M restaurants, on a one-dimensional street. All people are to meet at one restaurant. Find the restaurant where the total travel distance from all people to that restaurant is the shortest among all restaurants.
• The problem can be solved with brute force with O(n*m) complexity. The question is how to solve it faster than brute force.
• Describe the algorithm and why it is better than brute force. Coding is not required.

1. Coding question:

• Given a binary tree in memory (not sorted, not balanced), write code to serialize the binary tree to disk, then deserialize from disk and reconstruct it in memory.
• Runnable code is required. You may use any language you like. You may also decide the format on disk.

1. System design:

• 1 million backend servers that serve search traffic (think of it as a search service like Google).
• 10k frontend servers. The FE servers intend to act as load balancers for the incoming traffic to the BE servers.
• Incoming traffic to the 10k FE servers is not balanced: there can be cold FE servers and hot FE servers.
• Design the system/algorithm where traffic to BE servers is balanced.
• The design should be within today's computer architecture, ideally without centralized components.