In this article I link to two excellent articles on the subject of hiring coders. They're not new by any means, but if you haven't read one or both of them, I thoroughly recommend them. (If you're familiar with both these writers, then skip this article.)
Smart, and Gets Things DoneJoel Spolsky's 2006 article "The Guerrilla Guide to Interviewing" is a real classic that's since been made into a book. He argues that there are two things to look for when interviewing, and that a candidate needs to have both attributes - having just one is as bad as having neither.
"Everybody gives lip service to the idea that people are the most important part of a software project, but nobody is quite sure what you can do about it. The very first thing you have to do right if you want to have good programmers is to hire the right programmers, and that means you have to be able to figure out who the right programmers are, and this is usually done in the interview process."Read Joel's Article: The Guerrilla Guide to Interviewing (version 3.0)
Done, and Gets Things SmartSteve Yegge's 2008 response article reminds us that recognising smarts (in ourselves and others) isn't even necessarily possible. He suggests that the best approach to hiring is finding "seed" employees (although obviously being able to identify them is a Catch-22 situation). To find them you either need to be lucky, or perhaps home in on them via word of mouth.
"How do you hire someone who's smarter than you? How do you tell if someone's smarter than you? This is a problem I've thought about, over nearly twenty years of interviewing, and it appears that the answer is: you can't. You just have to get lucky."Read Steve's Article: Done, and Gets Things Smart