First round - Some questions on my prior work. Design distributed rate limiting system.

Second round - Design video sharing system where videos must only be visible to people user has shared it with. The focus was to make the writes resilient to any kind of partial or complete failure of subcomponents (2 Phase commit). In the end, we also talked about maintaining access control on shared videos.

Third round - This was a coding round.
https://www.geeksforgeeks.org/delete-n-nodes-after-m-nodes-of-a-linked-list/
Find given word in word grid. Words must be vertically horizontally or diagonally aligned. (Variation 1) Find a list of words in the word grid. (Variation 2) Words are being streamed as queries and grid is fixed.

Fourth round - Few questions about my background.
Leftmost right cousin of a node in a tree.
Reader writer lock.