The initial phone screen seemed to be mostly a get-to-know-you deal, just questions about my background and my experience using their SDK. Next came a simple programming project, with one week to complete. The problem wasn't complicated, but an experienced developer would be able to distinguish themselves. Be sure to test everything, and structure it like you expect it to become a larger project. When I submitted it, I felt like my solution was a bit over-engineered for a simple command line app, but the feedback I received on it was overwhelmingly positive. Next came a tech phone screen with two of the engineers. I had been told beforehand that they would be trying to discern my technical depth. They mostly asked about projects I had done and any challenges I had overcome while working on them. The day after the interview I received a call informing me that they weren't going to continue the interview process with me. The feedback I received was that the interviewers felt I had stayed too high level in my explanation of my projects, and that had raised some red flags for them. If you're like me and you have a hard time explaining things unless you draw them out, I'd suggest you ask if you can use some sort of on-line whiteboard during the technical phone screen.