Those are questions a manager should be asking, ie, outside the scope of the interview I'm conducting. They're also the easiest to fake. Everybody knows the answer is to say they write test cases for every change before they check it in. That's way easier to memorize than any coding puzzle solution.

I've had some frustrating experiences where the obviously talented candidate was nearly passed over because they didn't use the right software engineering buzzwords while at the same time the manager came close to overruling the technical veto because they felt some other idiot sounded like a good fit.

Teaching someone to write unit tests is, imo, far more likely to succeed than teaching someone to understand recursion.