I was able to skip the initial phone screen because I was an employee referral. The actual interview was a full day and focused mainly on technical aspects. Anything on your resume is fair game, even if it is more than 10 years old and is NOT relevant to the proposed position. Interviewers seemed more interested in finding out what you do NOT know rather than what you do know. One of the questions focused on command-line options for gcc, but totally ignored what I consider the real subject matter of the example design, which was the trade offs between dynamic and static memory allocation on a real time system. On the positive side, the interviewers were polite