Ask them to explain what 4-5 different bits of code do. When they do, ask them to explain it like they would to a junior and to a senior/principal/fellow. It w

Ask them to explain what 4-5 different bits of code do. When they do, ask them to explain it like they would to a junior and to a senior/principal/fellow. It works very well and takes only an extra 10 minutes on top of the conversation.