Interview on campus and was given an offer by the interviewer on the spot (something I had never seen before) only to have it pulled by HR and asked to interview on-site. HR Person/Recruiter was by far the least professional person I have dealt with thus far. Emails would be sent without a subject heading and the language in general was very informal and I was never reimbursed for my expenses. Interviewed with about 12 people in 4 separate group interviews, which included two tours of the site. Engineers were very professional and questions were mainly behavioral, some slightly technical.