My personal experience in hiring is that people should be able to explain concepts in a clear why. So usually I ask to explain an pattern that they say they hav

My personal experience in hiring is that people should be able to explain concepts in a clear why. So usually I ask to explain an pattern that they say they have experience in. I let him/her choose how they want to explain it whiteboard / pen and paper / words only, sitting or standing. I don't care as long as the person is good in explaining and has a firm grasp of the subject. Both are needed to do a proper job. There are lots of people that are unable to explain MVC in a clear let alone correctly even if they used .NET MVC or spring MVC (or whatever)for 10+ years. After that is seldom useful to ask anything else.. this approach had never failed me.