Advice for Interviewers

Before I forget my recent interview experiences, I thought I'd write about them a bit in that some could have been improved greatly, in my opinion. So if I were to be holding an interview, I would consider the following ...

• Use caution with written tests. They might be useful in situations where you want a candidate to explain something, and it shows a candidate's writing skills. But I think multiple choice and true-false questions are a bad idea. They're inflexible, so a candidate has no opportunity to argue his/her case - a candidate might be quite close to the answer but is unable to demonstrate that. And by all means, don't rely on a written test as the only means of evaluation - that's so impersonal and rigid.
  
• Set a relaxed tone. Interviews are awkward, and can be especially so when engineers are involved. Try to get the candidate to relax and open up. Otherwise you might be missing out.
  
• Pose a problem. Ideally, a problem without a single solution, with no correct answer. See how the candidate thinks about solving it. I really enjoyed such exercises.
• Ask a bogus question. Make something up. Ask the candidate about it and listen for his/her response. I think it's important for a software developer to be able to say, "I'm not familiar with that" or "I don't know". Ours is a profession where learning is constant, and a candidate should not pretend to know everything.
• Don't expect all answers to be correct. A software developer can be expected to have at least some skills in lots of areas: database design, algorithms, object orientation, data structures, enterprise libraries, web frameworks, AJAX interactions, web design, usability, quality assurance, software methodology. No one person can be an expert in all these areas. I'd recommend asking about the things that are important to your organisation. Or alternately, come up with a set of questions no one person could possibly be expected to answer completely correctly.
• Follow up afterwards. You've made an offer, and a candidate has accepted. But don't forget the other candidates, especially the ones who've made it to the final round. Each has given you hours of his/her time; the least you can do is acknowledge this with a few minutes of your time. When you write those "no thank you" emails, don't be afraid to include reasons why you went with another candidate - this is helpful information.