Ask HN: How to conduct interviews to identify hackers?

For starters you could check if they have a github account. This might not be the best indicator, but it could give you a hint.

You could explicitly ask for open source projects they have contributed too (or that they are following).

I noticed that a simple, open ended task with a lot of time to solve it gives you a nice idea. I'm not sure what kind of task would be applicable for you, but I do a simple database manipulation in python. Some people will just do the minimum that works (or sometimes doesn't), but some will send the whole git repository, show that they did tdd, generate documentation, handle logging/reporting, etc. It becomes obvious quickly who do you talk to.

These are done at home before the interview - I don't think we need to worry about anyone getting outside help to get a perfect answer. With the amount of bad/mediocre answers the onesI'm looking for tend to really stand out. And issues can be verified at the interview.

The trick is to invite people to go as far as they want instead of giving strict boundaries. And lots of time. If it should take an hour to complete, give out a couple of days before the interview anyway. If the answer is really good, the interviewed person will be able to talk for hours about the details.

A few suggestions.

I'd avoid a maximal test as a basis for your decision. It's fine to test to make sure a potential intern has the technical knowledge to succeed, but studies have shown that given a familiarity with the subject, real world ability is largely not correlated with being able to do really well on a test of how fast/smart they are on a test. What seems to be a good predictor is something called grit... Basically how well a person deals with setbacks, keeps moving, perseveres etc. You should ask about setbacks and challenges they have faced and how they dealt with them.

I recall that there are grit assessment tools like questionnaires; I know West Point recently began to use one for it's cadet applicants. There may be one available online.

Remember that good hackers may be introverted, shy, or lack social skills. People have inherent biases against such people, tending to think of them as less intelligent and capable. Also remember that people have a bias and will rate more attractive people as smarter, more competent etc. Try to be aware of these inherent biases. so you pick the best candidate on their ability and merits.

Hope that is helpful.

Ask them some basic coding exercises. Mind you, I don't mean testing them on specific knowledge of a language (e.g. "does java always pass by reference?") but rather testing how they solve a specific problem. Iconic, overused example of this is reversing a linked list, though by now I feel like everyone has memorized how to do it because it's such a common interview question.