There was no phone screen and the first and final step in the process was an onsite interview. About a dozen people were interviewed at once in a conference room (which was convenient because I was able to carpool). They gave you a laptop and a test on C++ to work through, then there was someone in the room to check you off. Felt a bit like a lab in college. The questions were easy if you have a lot of experience in C++, they concentrated completely on C++ though. No algorithmic or CS-type questions. If you want to practice, practice coding in C++.