The OA was a straightforward procedure with 3 steps. 1) DS&A round, 2 hours for 2 LC hards. Basic concepts, just a lot to read and a lot to write code wise. 2) Multiple choice questions. 20 min for 20 questions. Required pretty deep knowledge on multi threading, networks, algos complexity, and OS. 3) Zap-N - a set of mini games to check for reaction and risk management.

As soon as my CV reached them, I had 7 days to complete a HackerRank and 2 more tests. It took them from Monday morning (when I submitted the coding test) to Wednesday evening to reply.