This must be highly cultural. After you done the interview, shook hands and thanked the interviewer there in person there is little point of follow up other than an opportunity of reminding of yourself in the consideration process.

Every interviewer seems to have some set of these weird little expectations about behavior, that are basically arbitrary. Worse, some are mutually exclusive (maybe not so much in this case—though, see elsewhere in the thread where someone mentions this seems like a fresh-out-of-code-camp thing, so it might send a negative signal!) so lots of rejections end up having a reason behind them, but a very stupid reason that you can’t really defend against, to be blunt.

> If someone doesn't send a thank-you email, don't hire them.

You may be missing out on a lot of potentially good people.

Alternatively, maybe they're dodging a bullet. ;)

I have no problem with thank you notes; I think they’re courteous and easy to send. It never hurts. If you don’t get hired you lose nothing, and if you do, you’re starting on a pleasant note.

But I would definitely want to know more about the governance of an organization that can sustain such a policy as categorically rejecting a candidate (read: contribution) for not meeting an unexpressed expectation.

As a UK interviewer I'd find them both unusual and annoying.

We already discussed you immediately after the interview. It's not going to change anything, but it might hurt your chances if it comes across as cringy or brown-nosing - we're also looking for cultural fit, and most Brits just don't do that. If you introduced new information in the email, you're probably going to force us to discuss you again, which is at best annoying and certainly burns up staff time.

So in a UK context, you're best off just saying "Great to meet you all - hope I'll get to work with you" at the end of the interview, and leave it at that.

Bullet dodged IMO. I'd rather work somewhere where talent, productivity and genuine charisma gets me ahead instead of ass kissing (yes, it's always ass kissing... These letters are never sent out of a genuine gratitude for being able to interview with you).