[ismarc]

Things I use that signal the same thing that a college degree (in any subject) does: Military service, long-term contributions to an open source project (even if it's their own and no one uses it), long-term personal projects (such as restoring a car, being in a band, participating in a gaming group) and being employed at a single company for 3+ years. None of these things are easy and rosy the whole time, there's conflict, potential disillusionment, the luster wears off of them and they require real work to accomplish (you can't just kinda half-ass them). For younger developers (sub-25), a college degree (even an associates) of some sort is the most clear on paper before you've had a talk with them. However, you can easily find out if there's anything like that by asking them what they do for fun and leading into things not directly related to their potential position (I typically lead with an example of how I like to work on cars, so I buy a classic car in bad shape and fix it up over 3-4 years, sell it off, then repeat).