Joel Spolsky has a great article on The Phone Screen, prompting me to jot down my $.02 on the topic.
In a prior life, I used to do tons of technical phone screens for everything from C# developers to Linux sysadmins. There is one concept that drives my interviewing style: You never have to ask a Navy SEAL if they can swim.
Here’s why: There are many skills, experiences, etc. that intrinsically require mastery (or at least competency) in smaller supporting skills. I’ve found that if I can validate these higher-level skills, I can reasonably assert that the candidate is competent in a cascade of supporting topics. It also allows you to sidestep the Buzzword Bingo that so many candidates feel that they need to play.
I like to ask questions that intrinsically flush out other areas of expertise (or lack thereof) in the process of being answered. For example, I never ask someone if they are proficient in [INSERT TOPIC HERE].
Rather, I ask them what they like or dislike about it, and why. If they have an opinion regarding likes and dislikes, it’s usually grounded in an understanding of the topic at hand, plus some basis for making the comparison. Plus, I’ve found that canned answers regarding opinions are easier to sniff out, because there’s no heart behind them.
The folks that eat and breathe technology have lukewarm opinions either way on very few topics.
I also ask a lot of questions about failures, bad designs, etc. I’ve found that for every big project, there are a bunch of junior folks who wait two years and then profess to be the project lead. The imposters always remember the cool stuff and the brag-worthy statistics (”we saved the customer $30M…”). However, only the genuine project leads can speak convincingly about the all-night debugging session in the office with the CIO the day before the big demo, the nasty integration details, hard-to-reproduce library conflicts, etc.
Also, here’s one more tip: I’ve found that if a candidate ever answers a question with word “Polymorphism”, they are always trying to bluff their way through the interview using big words. I know this because I never ask questions where the word “Polymorphism” by itself is a reasonable answer.
