TikTok SRE Engineer interview questions

Three rounds, the first round is I would describe as a leetcode easy. It wasn't even an algos question, just making sure you know how to read some text and write some code with it. Second round was a SRE technical round, there aren't really any difficult questions you would need to prepare for here, and the final round was some scenarios based questioning, an SQL type question, and then we had about 15 minutes left for a systems design. I asked my interviewers for feedback throughout the process and it all seemed positive, so I really don't have a clue why I was rejected. No follow up call back for feedback either.