The Most Common Interview Question

April 3, 2007 on 4:33 am | In Job Hunt |

I’ve been asked this question enough times now that I might as well put it up here for others to ponder. Question first, and comments and discussion after the jump.

You type a url into your web browser, and then press enter. Describe everything that happens from that point onwards in as much detail as possible.

The devil is in the details.

I’ve had a couple reactions to this one from other people I’ve mentioned it to. A few people have a knee-jerk “Oh, that’s easy.” reaction, and ramble for a few seconds about getting the content from the HTTP server and then sticking it on the screen. But, as anyone who’s ever written any software can tell you, it’s easy to describe in broad sweeps what’s a complete nightmare in implementation.

One of the nice things about this question is that it can be used to focus on a wide area of topics, depending on the interviewer. If the answerer is allowed to ramble on, a good picture on what areas of the operating system they’re most familiar with will quickly begin to emerge. Do they elaborate on the rendering process and HTML parsing? How about the underlying event system of a windowing operating system? Hardware events from the keyboard? TCP negotiation steps? Caching? Proxies? Server design?

It’s the kind of question that doesn’t put the interviewee on the spot or increase the pressure, but instead lets them spill in useful fashion. If you’re interviewing for a specific job, guide the candidate towards those areas that are the most valuable to you, and see what comes out. It’s an execellent question for a phone interview, simply because it’s all dialog without any uncomfortable pauses or out-of-view scribbling on notepaper.

That said, having answered it a couple times myself already, I think that’s quite enough :)

Cheers!