My philosophy is simple "if you're not nice, you can't work on our team; I don't care how smart you are!". The reason is, when new employees don’t work out, it's rarely due to lack of experience or incompetence; it’s usually their inability to work well with others.
So instead of only evaluating candidates on their abilities and experience, screen to figure out if they're a jerk.
Here's some question to ask to determine if they’re a jerk:
The first question can be "Tell me about yourself, but you can’t mention anything that’s on your resume." What you're looking for is an attitude of curiosity and openness.
The second question should be “thought-provoking” to test how candidates think on the spot; e.g., “Which country will be the first to make it illegal for humans to drive cars?" There isn't a correct answer, only a wrong one, which is freezing up and saying "I don’t know."
The final question can be “rate your knowledge of technology trends on a scale of 1 to 10.” Anyone who answers 9 or 10 should be red flagged. It’s great to be an expert in certain things, but since technology is continually changing, anyone who considers themselves a 9 or 10 is overhyping their know-how.