This is a good comment. One thing I'd like to point out is that people often defend technical interview exams on the notion that if someone can't write a facto

This is a good comment. One thing I'd like to point out is that people often defend technical interview exams on the notion that if someone can't write a factorial function, that's a bad sign. Well, sure, but my experience has been that the technical interview exam is far more elaborate than this. My questions were more along the lines of finding all permutations of a set (usually with some twist, like find all permutations that, when combined, match another member of the set). Or finding all matching sub trees in an binary tree, or something depending on merge sort or quick sort. That sort of thing. Nothing impossible, but considerably more involved than simple recursion. And the teams that interviewed me clearly did expect to see largely working code written on a whiteboard. Overall, it's elaborate enough that people do need to study substantially for their interview exams, and good developers may simply decide they don't want to waste the time on a job that might not even come through anyway. I once learned to do intricate integration by parts in calculus, but I wouldn't be especially interested in training up to do it for a data science interview. If it comes up for reals, I'll deal with it. This is something the industry has inflicted on itself, which is why I feel a lot of irritation when I hear the same companies talk about a severe shortage of talented software developers.