The Programming Interview Experiment

"Bring the source code—we’ll ask to take a look at it."

Seriously?? What actual company do you know that would allow its IP to walk out the door? And possibly to a competitor?

Additionally, projects are usually the work of a team, and are heavily iterated upon. "your contribution" is usually hundreds of little changes building upon other changes, not "this is the application I wrote".

I've been burned too many times by people who can talk the talk, but cannot walk the walk.

Design, data structures, development methodologies, etc, they knew it all. But ask them to code a simple method (find the intersection of two lists) and they take an hour to deliver a barely-working, sub-standard solution.

Trust but verify.

To start, I think your interviewing practices are significantly better than the stock whiteboard-based version (and your criticisms thereof are spot-on).

That said, some concerns:

Leading with the source graph challenge seems a bit much. My experience has been that it’s necessary to have at least some filter for the unwashed masses before requiring that much work of someone. At my last company, we had a 30-minute non-technical talk with a founder (later replaced by our well-trained recruiter/office-manager). This helped filter out the people who weren’t what we were looking for at a really high level (e.g., an ops engineer applying for a dev role, a really junior person applying when all we have room for right now is a senior one, a dev who only knows pascal, etc) before making them invest the time required for an in-depth take-home test.

Also, what’s with the 24-hour limit? It seems too long to prevent cheating, but short enough to be annoying. For similar challenges, I’ve given people as long as they want (up to a few weeks), but asked for a blow-by-blow writeup of how it went and how long it took them. We may have gotten some liars, but we never had someone arrive on-site who claimed it took them 2 hours when, based on their skill, it probably took them much longer. People seemed reasonably honest about it, and the convenience seemed to be appreciated.

Asking to see source code for a significant project is tricky. I know good developers who wouldn’t have any code to show for that because everything significant they do they got paid for, and can’t in god conscience show to someone else. For example, I worked pretty long hours at my first job and built some interesting stuff, but I didn’t have much time for side-projects because of it. A friend of mine works normal hours now, but does contracting on the side. Plenty of good code, but nothing he could show to someone else. That said, asking to see some source is very high-signal, so it may be worth the tradeoff of only selecting people with significant free side projects.

That said, it’s still a way better process than teasers and whiteboard algorithms. If I were looking for a job, I’d definitely apply. :)

Interesting- I have the opposite reaction. I would (and have) refused to work for a company that doesn't ask me to code in an interview. It may be nice for me, but it means they probably didn't ask my potential coworkers to code either, and I don't want to work on a team picked like that.