I applied in mid-July, was asked to fill out a security clearance pre-screening form in late August and was asked for my interview availability about three or four days after submitting that form. I had an hour-long phone interview with a recruiter and two software developers. The questions ranged from simply describing my resume and past projects, to my interests outside of computer science, to some technical questions. I didn't have to do any sort of code debugging on this call, but they were definitely checking to make sure I had basic computer science concepts down, so be aware of basic OOP concepts, very general knowledge about types of data structures, and software engineering basics. The call was very pleasant overall! I got an email the next day that they were working on my job offer (and I'm planning on accepting but still negotiating terms at the moment).