I once interviewed for a CTO job at a 12-person company. The CEO interviewed me by asking me three different “brain-teaser” questions, none of which had anything to do with managing a team of engineers. They did offer me the job but I turned it down (for various reasons, but this was a contributory factor). I resolved afterwards that if I was ever offered a brainteaser again I would say “Please don’t let’s waste both our time on this. Ask me about my experience or pose a scenario, but I will not do your brainteaser, and if that’s part of your process and can’t be skipped then it’s better that I leave now.”