When I interviewed for my current job four months back, I was put through over twelve hours of high-quality interviews. This includes both telephonic and face-to-face processes (on one day, I was called to the office and grilled from 1030am to 630pm) and by “high quality”, I’m referring to the standard of questions that I was asked.
All the interviews were extremely enjoyable, and I had fun solving the problems that had been thrown at me. I must mention here that the entire process was a “stud interview” – one that tried to evaluate me on my thought process rather than evaluating what I know. I’ve also been through a few “fighter interviews” – ones where the interviewer just spends time finding out your “knowledge” – and I don’t remember taking a single job so far after passing this kind of an interview.
So recently I read this post by Seth Godin that someone had shared on Google Reader, where he says that there exists just no point in having long interviews and so interviews should be kept short and to the point. That way, he says, people’s time gets wasted less and the candidate also doesn’t need to waste much time interviewing. After reading that, I was trying to put my personal experience into perspective.
One thing is that in a “stud interview”, where you throw tough problems at the candidate, one of the key “steps” in the solution process is for an insight to hit the candidate. Even if you give hints, and mark liberally for “steps”, the “cracking” of the problem usually depends upon an insight. And it isn’t fair to expect that an insight hits the candidate on each and every question, and so the way to take out this factor is by having a large number of questions. Which means the interview takes longer.
The other thing about the length of the interview is signaling. Twelve hours of hardcore problem-solving sends out a signal to the candidate with regard to the quality of the group. It gives an idea to the candidate about what it takes to get into the group. It says that every person working in the group had to go through this kind of a process and hence is likely to be of high quality.
Another thing with the “stud interview” is that it also directly gives the candidate an idea of the quality of the people interviewing. Typically, hard math-puzzle based interviews are difficult to “take” (for the interviewer). So putting the candidate through this large number of math-problem-solving interviews tells him that the large number of people interviewing him are all good enough to take this kind of an interview. And this kind of interviews are also ruthless on the interviewer – it is usually not hard for a smart candidate to see through it if he thinks the interviewer has just mugged the answer to a question without actually solving it.
All put together, when you are recruiting for a job based on “stud interviews”, it makes sense for you to take time, and make the candidate go through several rounds. It also usually helps that most of these “stud interviews” are usually fun for the candidate also. On the other hand, if you are only willing to test what the candidate knows and are not really interested in the way he thinks, then you might follow Godin’s suggestion and keep the interview short.