I don't ask candidates these kinds of questions in my interviews. For a coding interview, I'd normally ask them to implement something like backend rate limitin

I don't ask candidates these kinds of questions in my interviews. For a coding interview, I'd normally ask them to implement something like backend rate limiting logic for an authentication service, and continually ratchet up the complexity on each successful implementation until the end of the interview. I was asked the two sum problem in an interview once, but I forget if it had this constraint or not. This seems much more reasonable.