Comment by josephg

> who can pass this except recent college grads?

I can. So can a lot of the better candidates I interviewed. Most googlers and fb engineers can pass this stuff too.

Theres a much better way to test for senior engineers though, and it’s this: prepare a small program (200 lines or so) with some bugs in it. Write a few test cases which highlight the bugs. Then give the candidate the code and the tests and ask them to fix the buggy code.

Good senior engineers - in my experience - aren’t better than smart young grads at programming. But they’re soooo much better at reading code and debugging it.

I interviewed this insanely good Ruby engineer once. He had the body of a bear, and a bushy, greying beard to match. During the interview he gave me a masterclass at debugging. Before he even looked at our tests, he read the code and named out loud assumptions he was making about it. Then he started writing his own test suite to validate those assumptions during the interview. He fixed a few of our bugs before he even looked at our tests, in the first 10 minutes of the assessment. And he fixed another bug we didn’t know about. I can’t remember how he did at the programming section of our interview. But I’d hire him in a heartbeat from watching him debug.

The one thing to keep in mind if you do this is that most people will overestimate how much debugging you can do in half an hour or an hour and overcomplicate the program you give candidates. If you make a test like this, make the code simpler than you think and actually calibrate its difficulty with your coworkers.