[bootsz]

My experience confirms this as well. I’ve interviewed at most FAANGs and many others, and made multiple attempts at some. Brute-force practice (e.g. leetcode problems) and memorization is the only thing that ultimately worked.

It would be nice if interviews really were a “collaborative” experience to see “how you think” where finding the optimal answer “doesn’t matter”. But it 100% does.

[Bartweiss]

Years ago, I had the rare experience of being told why I didn't get an offer from a big Valley tech company. (Not FAANG, but perceived similarly.) It was for an internship, and I suspect they wanted to keep candidates interested for full time applications.

The relevant interview was a "find the palindrome" question for which the desired answer was Rabin-Karp. The rejection was explicitly "your solution to the whiteboard algorithm question worked but wasn't optimal, so study your algorithms harder and try again in the future".

At the time, I thought it was pretty stupid that they tried to judge skill by requiring candidates to either have one random thing memorized or reinvent a publication-worthy algorithm in 30 minutes. But given the advice I got, it seems like the core motivation was "we want people who are willing to devote a bunch of free time solely to impressing us". And for that, asking impractical questions and demanding optimal answers works perfectly.