Best way to go is to ask them about their projects and hear them as to how they will explain them and how enthusiastic they are about building new things and as

Best way to go is to ask them about their projects and hear them as to how they will explain them and how enthusiastic they are about building new things and ask them to probably build one in 2 days with the help of google. Then i think the quality would just come out naturally and now you can decide whether to hire this guy or not.