Interviews for senior developers

Since I recently moved away from Microsoft and Washington to join Ericsson in California I recently did a number of interviews. And it was once again proof that most companies do not know how to interview in my opinion.

But it is not only my opinion. Others agree. And remember this is mostly about how to interview experienced developers. I think the approach to hire less experienced developers is different.

As pointed out in the linked article I find the typical white board problems superior in weeding out bad people you don't want to hire. But it also eliminates a lot of good candidates you want to hire. If you are OK with that it is actually a pretty time effective tool I think.

But when it comes to hiring experienced developers there are better ways I think. Because on of the most important things when it comes to working with experienced people there are many other things that are important than how they write code on the white board.

A few examples I've experienced and/or used myself that I think work well are:

• Have the candidate describe something they recently worked on. A senior developer should be able to explain any system to anybody. Challenge them and see if they are passionate without being defensive about their solution.
• Tell the candidate about something you worked on and have them design  it. A senior developer should not be afraid to have an opinion on something where you (should) know more.
• Give the candidate a simple specification and API and have them explain how they would use the API to implement then spec. A senior developer should be able to design simple systems from building blocks.
• Give the candidate some pretty ugly code and ask them for code review feedback. This way you will learn how they think about code and how they provide feedback.
• Use a few "litmus test" questions for things that are important to you. I like to ask the candidate about something they worked on that they are proud of as well as a real simple coding question that involves recursion.

To me the interview is not about getting the right answers. The interview is to get to know the candidate and their limits. Because an interview is in my opinion not to find a person with the right skill set but finding the right person with a known set of skills.

Also remember that whey you are the interviewee you need to learn about you potential employer. To do that I always ask one question to everybody I meet; if you could improve anything here, what would it be? I've learned a lot through that single question.