I valued open source contributions highly when I was interviewing candidates: it demonstrates that you're someone who is passionate about programming and enjoys

I valued open source contributions highly when I was interviewing candidates: it demonstrates that you're someone who is passionate about programming and enjoys building things in your free time. That's exactly the sort of candidate that I think a lot of startups ought to be looking to hire. But I think the question of open source contribution is completely different from "show us some code." The latter is intended to get a look at some of the actual work you've produced; the former is just another part of your work experience, formal or informal.