I live-coded Haskell a couple of times at job interviews for non-Haskell positions where you were free to choose.

It’s fun because the interviewer often doesn’t grok the paradigm. In one case, I was asked to make a password generator, and I went with QuickCheck’s Gen, which lets me write a random generator of things without explicitly defining a single function (they’re all monads).

So you go from somehow describing the thing you want to make to “I’m done.” :-D