On-campus interview consisted of two 30 minute interviews with 2 different partners. The following week I was invited for an office visit. The office visit was an all day event, and breakfast and lunch was provided. The morning consisted of a general presentation of the company and then specific presentations for each part of the firm (e.g., tax, audit, risk). Then we were taken to a conference room for a general Q&A with staff level employees. Throughout the question session, people were taken out for interviews. The office interview was 30 minutes.
The whole process was very organized and thorough. Very big 4ish.