* Interviewer has less experience than me and wasn't able to understand some concepts.
* Interviewer has no experience with the language I was using (and interviewing for).
* I solved all the challenges and answered all the questions, but the decision was no-go, for some reason (they don't provide feedback).
* I may be wrong here, but they also did recording without my consent. They should ask "Are you ok with recording?". Instead, they just record and violate California recording laws which require consent by both parties.
I think they did very poor job (however, I admit I am biased here). You need to be extra careful interviewing with them. There are some signs that their process is not organized and things don't work very well.