I'd add another one here - make sure you learn about the candidate prior to the interview. I once tried to hire someone who had contributed heavily to an open

I'd add another one here - make sure you learn about the candidate prior to the interview. I once tried to hire someone who had contributed heavily to an open source library we were actively using on a project. We didn't ask "what experience do you have with X", because we knew about this candidate's significant contributions to X. Unfortunately, a lot of recruiters are dropping a net across a river, figuring that an intensive technical screening will filter out the small number who can actually do the job. And of course, having done lots of tech interviews, I do understand why the technical screenings are done. But I also know that they can suggest a kind of laziness, an implication that you don't need to get to know a candidate's work, because if they can get through your screening, then of course they can code. But asking "what experience do you have with technology X" to someone who is all over the commit log for X can make you seem like the sort of company that isn't really aware of what's going on in your space. I didn't succeed in hiring the programmer I mentioned, but I'm pretty confident that we made a good impression on a strong candidate.