Round 1
https://leetcode.com/problems/keys-and-rooms/

Round 2:
Design system to store analytics like when user skipped advertise, when advertise in played etc.

Explained him about event driven arch, where event in every 15-20sec will be streamed to backend server, but he was not satisfied.
Did the devtooling of the same in hotstar website, they are using the same thing :).

HR mailed me about rejection next day.