I was asked 2 coding questions which I basically solved in 20 minutes. 1. count words in a string 2. find 2 numbers in an array that sum to a target number During the middle of the 2nd question the interviewer basically asked me to stop and said I know you can easily code this. He asked me the time complexity to which I answered ~O(NlogN). He asked if I could do better than that and he suggested using a hash which was fine. But then that would have meant using additional O(N) space as opposed to my in place sorting. Had a good conversation and was definitely expecting a call back for an onsite interview. 2 days later the recruiter emailed me saying the interviewer thought I did not have a good understanding of time complexity. What a piece of crap. If you are going to interview and analyze a candidate over a technical coding challenge after they are actually able to solve all questions, then you need to have better open minded people doing the interview. I could give the name out of the recruiter and the interviewer but rather not. Try and make sure your people have good interviewing skills and know how to select a candidate. 20 mins for 2 problems correctly demands an onsite interview call at the very least.