In my decades of programming I've never had to seriously consider these issues. I have used recursion and have written some pretty deep stuff like cryptography and writing my own interpreter (for a business - not a school project). I've even implemented recursion in a language that didn't support it. I have read about tail recursion several times. I still barely remember what it is. But I know a few books to reach for if I had to use recursion again. This is why the interview process is broken. I've written lots of production code and end up being seen as a lead programmer within weeks of a new job. And your questions would make me look like I don't know what I'm talking about.