Applied online and got a request for a phone interview after a little over two weeks. The phone interview was technical, and asked to send him some C code that implemented the usual linked list operations (insertion, deletion). Also asked about my experience in wireless (BTW this was for a embedded wireless firmware job, for which the business doesn't exist anymore).
The on-site was done a week later, which is faster than normal (usually they're 2 weeks after the phone interview). About 6 people interviewed me, each an hour long. The schedule was a little dynamic since they were busy, so some scheduled interviewers were replaced by other engineers who were last-minute substitutions. This can rub some people the wrong way, as it can give a bad picture of the organization of the group, but if you take it in stride then you realize that it just gave you a picture of how hectic the group is at the moment, so you can take advantage of the situation by saying how good you are under stress :).
Interviews were all in-depth technical questions; no behavioral questions other than the first one with HR. Two gave me embedded C questions (what is volatile, what is static, describe characteristics of an RTOS, how do you set bits in an int). One gave me a brain teaser (the one where a bird flies between two oncoming trains, and calculate how far the bird flew). One asked me questions about wireless protocols (WCDMA, LTE), how does initial access work, what are the control channels, what information was in each control channel, etc. All of them looked at the resume (as if it was their first time!) and asked questions about the work I did, and to describe it to them. This is fair game; if it's on your resume, you'd better be able to defend that you did good work and were at one time an expert on it!
The last one was the hiring manager, who gave me a mathematical question and asked me to solve it. He walked out after five minutes, then came back and asked if I had the answer. I did not, but explained my plan of attack to give him a sense that I wasn't stumped, just trying different ways to solve it. I eventually did, but I was upset with myself that I didn't get it right away. He explained that he wanted to see how I did under pressure, and emphasized that the job will be stressful at times.
