[foldr]

Anecdotally, I am one of the older people in our dev team, and also once of the only people who cares even slightly about big O. I’m talking simple stuff, like knowing whether indexing a given list data type is constant time or O(n). To be fair, it’s not particularly relevant to what we do.

[ericbarrett]

I think asking a candidate some basic big-O notation questions in an interview is great. Asking a DevOps candidate if a search algorithm developed and published in 2018 is O(n log(n)) or O(n log(n) K^(log n)), and then dinging them for not getting a perfectly correct answer, is over the top the kind of stuff that's used for age discrimination. Not because the young candidate will know it, but rather they will be excused for "almost getting it" and "having a good attitude" etc. in the hiring committee.