Randomness is definitely a factor, there are so many things that can go wrong, from having a bad day, an interviewer having a bad day, just bad luck on the set of questions you are asked, the list goes on.

I have performed a lot of coding interviews (probably 400+), I'm painfully aware of how limited the signal is that I can reliably read from 45 minutes with a candidate

I deliberately ask a question that has no algorithmic or data structure component to it (and tell candidates that) it's just a simple problem solving coding question which allows some insight into general coding and engineering chops

I still see experienced engineers struggle. It is hard to pinpoint exactly why, but lack of preparation/practice definitely seems to be a problem

Covid appears (at least for me) to have killed off the whiteboard

> I still see experienced engineers struggle

I've seen experienced engineers who I know for a fact can code and solve problems decently completely freeze and blank out during easy live coding challenges.

I think interviewing is a stressful situation. It's hard for reasons outside an applicant's knowledge or intelligence. Interviewing seems to be a skill in itself. I know I hate it... :(

I give out a certain coding question to my candidates. I recently interviewed and was given the exact question - and I blanked! Like, this was a coding kata style problem that I’ve done in several languages and seen done in others. I just absolutely blanked. Brains are strange.

Steve Yegge famously talked about Google's "interview anti-loop", where you get two interviewers in your process who wouldn't have hired each other, so the things one of them values are actually negatives for the other, and viceversa.

I don't know if that's still a problem at Google, but it could explain why some people don't pass the interview process even though they are reasonably clever.

From my more than 5 years at google I saw a lot of random stupid interview questions. I was astounding. 10 years ago they didn't seem to do any interview question checking, you could ask anything.

Sorry, "I was astounding" was meant to be "It was astounding". I felt only average at google ;-)

I was referring to tech interviews in general, not a specific company. Interviewing's like dating: if you do all the right things you may still not charm the person you want, but the odds are very good that you will be able to find a good partner.

People with MS and 6 years of experience are judged differently from fresh graduates.