[edhowzerblack]

You can learn a lot about what a developer knows and is capable of by talking to them about the projects they worked on. Ask them detailed questions about the particular problems they dealt with on projects and how they were solved. Ask them to explain core concepts that are intrinsic to the technologies they've worked with. You can also get a feel for their personality this way.

Remember, we're talking about a screening process. Once they come onsite for the real deal you can throw all sorts of stuff at them.