Domande di colloquio per Senior Java Developer presso Provar

First round is MCQ round and once you clear it you get spring boot assignment. The assignment itself is related to Salesforce APIs which is not properly described in the word document. I managed to sort the assignment incompleteness on my own and presented the code in first F2F technical interview. The interview went fine although I was not able to answer one question related to race condition in Hashmap. I got a reply from HR after multiple follow ups that I am not selected. I mean seriously, is race condition question is your selection criteria? The interviewers were quite dumb and it looked like they have studied first about the questions to be asked in interview. Very bad experience as I wasted 6-7 hours in writing the assignment only to be judged by race condition in Hashmap.