I did an interview for a Senior SDE at a hiring event. The process consisted of an online assessment followed by a day of onsite interviews. 4 rounds covering algorithms and design. The questions were fairly easy and I did very well in all the rounds. Cannot disclose due to NDA. I was expecting an offer and to my surprise got a generated auto response indicating a reject after a day. I had constant communication with the recruiter during the whole process and after the reject there was zero response from the recruiter regarding feedback. I honestly believe that the interview was just for headcount since I could not think of one reason why I could be rejected. I also saw the position that I applied for indicated "applications are not accepted" even before the interview.

I was asked at 8:30 for a hiring event. Had the first round from 8:45am, it was about Data Structure and problem solving. I solved the problems and further variants, thought it went excellent. Then had to wait almost an hour before the second interviewer came. He himself said he wasn't prepared and it was a last minute. Then he proceeded to ask a math related coding question. I couldn't remember the property so I needed help, then it turned out the actual algorithm/coding needed was almost trivial. Again I waited an hour without any information and then called up the recruiter and was asked to go for lunch. After lunch, I had a Systems Design round. We started from generic problem to more designs. I thought it went well. The interviewer did say the they didn't have feedback from 2nd round yet, only 1st round. After this, I waited a few rounds and was told the feedback wasn't positive and I am pretty sure it was the feedback from 2nd round and I just had to waste a few hours more due to lack of coordination on the recruiters' part. I should mention that the interviewees were polite and nice to talk to.