Why limit applications to programmers? I looked through manually and found about a dozen companies each with non-programming technical openings, such as for biologists, physicists, or electrical engineers. The "programmer-only" requirement seems self-imposed by the site, and it would be trivially simple to organize non-programming-centric engineering positions. The same puzzles could be used as a barrier to entry, as the same type of thinking is needed in solving problems in scientific research or hardware engineering.

It's very hard to find hardware engineering startup jobs, and this is a space where your site could really stand out.