How (Not) to Interview a Developer

My team has an open headcount for a developer and, if things go as planned, my team will have more open headcount for developers, so I've been talking with lots of developers. Coming from a marketing team and previous to that being a writer/editor for a variety of trade publications, I have a unique skillset for interviewing developers. That is to say, I have no skills for this at all. None, nada, zip, zero, zilch. Bupkus.

Yet, for the past two weeks, I've been talking to a host of people who've architected and built everything from sophisticated ASP.NET applications to complex VSIP plugins. Since most of the conversations are informational, I spend the time explaining about my project, about Microsoft, and about Seattle. I listen to the folks talk about what they've done, what they're most proud of, what the like the most about Visual Studio, what they hate the most about Visual Studio. 

As a marketing director, I could usually tell within 5-15 minutes whether a person would make a good Microsoft product manager, be a fit for the team, and be qualified for the specific role. Rarely did I need the full hour to get a sense. But here, on this new turf, I am at a loss.

So how do you tell in a one-hour interview whether a developer is going to have the skills to succeed?