> some programmers who didn't know a thing about my profile asked me to invent some algorithms on a white board for almost four hours.

Yep. Did the phone interview after weeks of back-and-forth, told them what I was interested in, told them I was only interested in working on such-and-such, then they drop me in the standard "write memcpy for us" interview. The last interview was some dude with a weirdly confrontational attitude who wrote some assembly on the board and said "Find the bug. It took us 3 months."

If someone like David Presotto or Rob Pike want to recruit me directly, fine, but after similar experiences with Amazon I've decided the typical mega-startup interview process is for the birds.