1. The interviewer asked me detailed questions on API, all were practical questions, not theory. I was able to answer all. 2. But he asked a coding question which later I found in Leetcode Hard level. I could not do it in 15-20 minutes so I got rejected. I'm sure had I asked him a similar hard-level question to solve in 15-20 minutes, he would have failed as well. Just to show off that their company is sophisticated, these guys are setting unreal expectations. So depending on this one question that I could not resolve, they disqualified me.