Ask HN: Developers: How do you explain to people what it is you do?

I try to explain what I do to people in a way they can understand. Rather than go into rote jargon about writing code and making objects extensible, I tell them that I have puzzles and tell a computer how to solve them as efficiently as possible. I think that sometimes gets through, but I feel like it still misses the mark.<p>So how do you guys do it?