The campus interviewer had a hardware background and he hammered me with hardware questions which were difficult for a computer science student. When I muddled through them, the interviewer mentioned that he was impressed I was able to handle new subject material. My point in mentioning that is just that the campus interviews are limited by the people they have on hand, and were more difficult than they needed to be. When I got to the on site interviews, my interviewers were all software engineers. Their questions tended to be reminiscent of what I've experienced at other companies.