Why do coding tests?

“No, coding on the whiteboard or on paper, or even the 5 minute exercise on the laptop is not really coding.” 

It doesn’t matter whether or not it’s “really coding”. All that matters is how effective it is in evaluating your candidate. 

I have interviewed over 2,500 devloper candidates and every single one has had to code with pencil and paper, in a room alone for 15 to 30 minutes. This has always been, by far, the most effective thing I could have done. 

I never cared what they actually wrote. I never once found out if it would even compile or run. And I never cared. The only purpose of the coding problem was the “discussion afterward”. This told me volumes. 

Given a person, a discussion, a problem, and 1 to 3 pages of written code, I could ask many questions focused on a single issue and take it any direction I wanted. And learn what I needed to know about that person… 

How did they attack the problem? What did they feel comfortable using? How did the deal with the situation? 

What kind of attitude did they have? How much did they enjoy dealing with the problem and discussing it? 

How well did they defend their choices? How willing were they to take criticism? How willing were they to stand up for what they believed in? 

These are the things I want to know now. Not 3 months after they start working. Programming with pencil and paper and discussing afterward is the best way I’ve ever found to find these things out.