I'll be the contrarian and claim that inverting a binary tree is a perfectly reasonable interview question. (Although not anymore now that it's famous). It combines basic background knowledge (what is a binary tree and how is it structured?), ability to reason logically (binary tree algorithms are often recursive, "inverting" a tree with no children is a no-op, otherwise you want to swap the children, and the children's children, and...), and enough familiarity in one language to write simple constructs without an IDE or stackoverflow holding your hand. None of this requires you to be Jeff Dean.
I will agree that the guy who kicked all this off has a legitimate complaint if the recruiter failed to adequately explain the interview process, and I'm sure there are lots of bad interviewers that focus on meaningless details or obscure trivia. But I don't agree that the concept of having candidates write code is fundamentally awful.
I will agree that the guy who kicked all this off has a legitimate complaint if the recruiter failed to adequately explain the interview process, and I'm sure there are lots of bad interviewers that focus on meaningless details or obscure trivia. But I don't agree that the concept of having candidates write code is fundamentally awful.