I met Intel recruiters at a conference in the Portland area. As luck would have it, one was a past acquaintance of mine, and he personally took my resume and passed it along to interested managers. What followed was a frustrating series of several weeks of missed late-night phone calls and sporadic emails with a couple of hiring managers. Eventually, though, I had an hour-long phone interview with a hiring manager. We discussed my experience, PhD research, and career goals in great depth, and at the end of it, he asked me to fly out for an in-person interview 8 days later.
I was asked to prepare an hour-long presentation on my PhD research, and given a precise schedule of my interview (8:30am - 6:30 pm!!!) several days ahead of time. Intel arranged my flight, rental car, and a very comfortable hotel near their campus. They also reimbursed my food and other expenses with a generous flat fee and no hassles.
My interview consisted of my hour-long presentation and Q&A, then about 12 one-on-one meetings with members of the group I would join, everyone from young engineers who had been there for 2-3 years to a VP who had been with Intel for 20 years. The younger guys mostly went first. They asked extremely smart and detailed questions about my research and experience, and explained to me some of their group's organization and basic analysis techniques and processes. I was glad that I wrote lots of this down, as I met more senior managers later, and they were clearly looking to see that I had gained a better understanding of individual members' roles and could intelligently discuss the group's workflow and goals.
There were no random problem-solving questions, but I did have a couple of pertinent "gotcha" questions about relevant statistical analysis and basic CMOS design, which I answered fairly well. Many picked oddball elements of my resume, included hobbies and unrelated academic interests, and asked me questions about those.
During my hour-long lunch break, 4 younger group members took me out to a nice restaurant and were sociable but kind of hands-off as if they'd been instructed to give my brain a break, for which I was grateful.
I've read on hear that other candidates seem annoyed by Intel's practice of having many interviewers ask similar questions. I do not think this is accidental, and saw lots of evidence that interviewers were talking to each other behind the scenes. I think Intel's interview is meant, in part, to be a test of stamina: can you talk about yourself and your experience intelligently for a whole ten hour day while keeping a patient and cheerful disposition, and learning something about the company as well along the way?
That being said, all my interviewers were extremely courteous in terms of offering me plentiful coffee/juice and bathroom breaks throughout the day. Individual interviews started and ended precisely on time.
My final interview was with the hiring manager who had done my phone interview. After the final interview, he told me on the spot that I had got the job and that a formal offer would be forthcoming in a few days. This was conducted via a phone call with an entirely separate HR manager. My offer was very generous, and I did not need to negotiate anything.
Intel's interview process struck me as extremely smart and well-designed. In addition to them learning a lot about me, I got the feeling that they were trying to make me enthusiastic about their group, and to encourage me to want to be a part of their "club." It worked. I can see this being frustrating for less sociable candidates, but that's part of what they want, I think.