Interesting. Many (if not most) of the engineers I met in my earliest jobs were moonlighting. How common is such an anti-moonlighting clause in employment contracts?

I'm not sure, but that sounds unenforceable in the state of California (where a lot of HNers are). If you work outside of California, sucks to be you, I guess.

Interesting point! As far as I know we've never run into this issue. We are in The Netherlands, so perhaps that makes it easier. However, were this ever to become an issue with a particular candidate, I'm sure we are flexible enough to work around that. The two day try-out isn't set in stone, it's just a way for us (and for the candidate) to see if we like each other. There are plenty of other ways to solve that if a try-out poses legal issues.