I did a lot of technical interviews for the software company I worked for (I'm in grad school now) and there was a lot of disagreement between different interviewers in our company. So I can tell you the kinds of things I looked for, but other interviewers (yours, for example) may have different opinions.
In general, think out loud. I often gave problems that I didn't really expect the candidate to be able to answer on the spot. I was more interested in seeing the false starts they made and trying to understand their thought processes. Candidates that described their thoughts well and described how they would approach a problem (before starting to write code on the whiteboard) almost always came out ahead. We'd talk about their ideas and I'd nugde them in the right direction so when they came to the finer details of the solution, they were much more likely to be on the right track and I understood exactly what they were doing. Much better than someone who launches right into something and I have no idea what they are thinking. Good people usually asked a lot of questions to make sure the understood the problems I was giving them and even offered an example to make sure (which is a great trick--if you don't understand a problem well enough to come up with your own example you probably don't really understand it).
I had my share of candidates who talked too much (so we didn't cover all that I wanted to cover) as well as those who were too quiet (hard to get information from someone who answers things too briefly). I could always tell when people were evading my questions and I could usually tell when they were BSing--don't do it. I usually asked them about their experience in general terms to see how they described themselves, then I started asking specific questions (making them write code on the whiteboard or describe specific details of projects they'd been involved with). That usually gave me enough information to break their individual code--if the glowing praise they gave themselves on one project translated to their lack of knowledge about the specifics of that project then I assumed the same was true of all the other stuff they said.
For me, people looking me in the eye and saying my name and all that stuff the interview counselors advise didn't make much difference. Clear communication and honesty was always more important, and of course, the actual technical qualifications. It's surprisingly easy to figure out when someone is full of BS.
Your mileage may vary, but that's my advice for technical interviews.
- Russ
