First, I had an introductory call with the recruiter. Later, it proceeded to the Loop interview, which consists of 4 rounds:

1. Data Structures and Algorithms
2. Systems Design
3. Behavioural round (leadership + overall fit/bar raiser)
4. Role specialization (Android)

I completed my whole process within two weeks. Each round was perfectly completed with its given tasks. I completed all coding challenges with successful test cases and expected output, and gave clear explanations during the interview. Each interviewer was satisfied with my output and result. I almost completed each round within 45 minutes, leaving 15 minutes for coding rounds. That's how fast I completed my coding rounds with utmost perfection, but still, I got feedback saying all coding rounds were sent as no hire.

I don't understand what went wrong, even though I completed them with running test cases and clear explanations for each code for each round. Still, I got a reject. I feel they were simply conducting interviews for fun.

Got an iOS developer for my algorithms and data structures round. The HackerRank IDE doesn't have Kotlin as a language. I had to do it externally in an online compiler and successfully completed it. The interviewer had no clue what to ask, as I completed my task in half an hour. He doesn't know about Android, so he was asking me what differences I found in iOS and Android, some basic questions which I answered. But still, I got a 'no hire' as feedback. Literally felt like a waste of time after giving such good performance.

Question on Binary Search Tree