I was contacted by a recruiter through LinkedIn who set up an initial call with the hiring manager. The hiring manager explained a bit about the company and it was a nice conversation. After that, they sent me a Hackerrank challenge, which consisted of 3 questions to be done in 2 hours. I was able to solve all of them but couldn’t optimise owing to the time constraint. They sent me a rejection email 2 days later. What surprised me is how they rejected me, even after providing working answers to all the questions. Very frustrating !