On-campus interview and then on-site interview. Standard interview questions. They don't expect you to know anything about mainframes during the interview process. Group panel that discusses your skills and why you would be a good fit for this job. If you participate in their internship (accepted into their internship) odds are you will be offered a full time position.

I had a great interview process. I enjoyed my experience a lot. The communication was great and the next steps were very clear. The recruiter was very professional and friendly.