TikTok Backend Developer interview questions

I had four rounds of interviews. The first round was a coding round where I was asked a leetcode hard problem, the second round was a low-level system design round which was pretty easy. The third round was a high-level system design round and finally a behavioral round with the hiring manager.

Phone screen with recruiter followed by 2 technical interviews on Hackerrank. Had some delays in the interviews when the engineer didn't show up, but was smooth after that. The questions were Leetcode medium type.