I applied through a recruiter. The process took 1+ week. I interviewed at Deloitte (Minneapolis, MN)
Interview
I met the recruiter at a career fair and was emailed to set up a phone interview with a senior manager. After this I was invited in for a series of interviews all consisting of behavioral questions
For now I only did the first round, so this information is only about this round. They do a series of group interviews with roughly 40 people each at each session. First you get some breakfast with the whole group and then a company presentation. Afterwards you get to read an information leaflet on the case you'll be doing, and you will be divided into groups of 4. In these smaller groups you get about 30 minutes to discuss the case and come up with a presentation. There's essentially nothing you can do to prepare the case interview, and there is no need to.
I applied through college or university. The process took 2 months. I interviewed at Deloitte (McLean, VA) in Oct 2014
Interview
I got into the on campus interview and was selected to a second/final round on site interview. There were three interviews with different employers at the company and a meal with other associates during the final interview. The interviews were all basically behavioral, based on background and project experience. There were a lot of follow up questions based on my answers in the interview, so it is very important to know every detail of the project or experience that you are talking about. The people I met during the interview process were all super nice and helpful. Some interviewer might appear to be a little harsh. Be calm and confident under any possible pressure in the interview.