It might seem like a big scary test, but it's not. Sure, that's how things were in academia where you've been most of your life, but interviews are only superficially like tests. So the first thing is, stop worrying about the outcome and focus on the problem you are trying to solve. Not, 'how do I pass this interview?', but 'is this the right job for me?'. As soon as you start thinking like that, you'll see that you and the interviewer are there to solve the same problem, and you are on an equal footing.

The question 'is he good enough?' is just one among many - and at this stage it's the one you can do the least about, so try to let go of that. Sure, you can study long-term and increase your chances of passing certain types of technical interview. But if the job is really a good fit for you, you'll already be doing that kind of study because you're interested regardless of whether you need it for an interview.

Of course, practice is still useful. Don't just practice being interviewed, practice giving interviews - then you'll get an idea of what the interviewer is thinking. Will this guy fit in my team? Is he going to stay interested in the job?

One other tip- try and make sure you have other possibilities before you go into an interview so you don't have to feel like everything is riding on this moment.