Jeffrey Palermo has shared his opinions on Interviewing.
Some of them I agree with, some I don't. Rather than a point by point analysis of his post, I figured I'd share some of my experiences instead.
I look for attitude more than I do for aptitude. Aptitude can be taught, attitude cannot be - atleast not quickly enough.
An in-person interview is extremely time consuming, so I am very picky about who spends their valuable time walking into our office, and sitting face to face with me. When you do sit face to face, cutting an interview shorter than 45 minutes is unjust and rude, and being rude is not an option. The candidate you turn down will invariably feel bad, and the world is a too small a place to make anyone feel bad.
In those 45 minutes, I try and explain what the job will entail on a day to day basis. I try and ask a bit about the candidate without being too invasive of their personal lives - my intention is to ensure that the job fits their lifestyle. If they have an issue with a friendly chit chat around personal life, they are probably not good company anyway. (Of course there are limits).
Finally, for the tech part, I ask them "What they are good at". There is so much to learn, it is impossible to know everything. I then cook up a practical problem on the spot, in what they are good at - and bordering something they haven't had much experience with, and give them a computer, internet connection and peace to figure it out.
I leave them alone for a few minutes, and when they are in full-flow, I interrupt and discuss their approach.
I am generally looking for, their logic, how they dig for information, design patterns/good coding, and in the discussion I look for their ability to communicate and understand technical chit chat.
I also try and pick a perfectly good point they have, and just to be an annoyance I put them in a corner and criticize their approach - just to see how they handle criticism (good team workers do not mind criticism).
I squarely avoid know it all phonies/cowboys. They do more damage to the team than good. No you don't have to be servile and meek either. More often than not, the cowboys know very little and are extremely bad at handling criticism.
Finally, if possible, I like to delegate out the job of interviewing to the actual people the candidate will be working with. Interviewing is quite a thankless job. You have to kiss a lot of frogs to find the prince, and frankly the frogs you kissed are never counted - but the time spent is still time spent. Not to mention, each one of those frogs that you rejected now has their ego dinged by you .. well some of them do.