“Let’s take a break from talking to people. Why don’t you have a seat in this empty office, and write a small program. Use any language you want to. The program can do anything you’d like. I’ll be back in about 30 minutes, and ask you to explain the program to me.”
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It seemed reasonable, if the job was programming, to ask people how they felt about actually doing some. And sure, it caused interview stress. We allowed for that in our evaluation; but the job was going to be stressful at times too, and we needed people who could enjoy it. The important thing was not what the candidate wrote, but the account he or she gave of it.
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And you’d be surprised how many people couldn’t do it. Couldn’t write a simple program and talk sensibly about it. They’d huff, and bluster, and make excuses, and change the subject, rather than actually write some code. “Oh, I think of myself as more an architect than a coder.”