The job was posted on my university career site. I applied and had an initial 1:1 interview with an HR V.P. They called me the very next day to set up a second on site interview in New York 3 weeks later. Roughly 10 candidates were asked to come onsite to interview. It was a two day process. Day one was dinner with senior hr professionals and v.p's. The next day consisted of 3 1:1 interviews, including a case study discussion, a panel discussion and lunch.
The process was all expense paid and the people were extremely nice and approachable. I was called and offered the job the very next morning.
My advice: Be on top of your game at all times and be yourself. Its okay to not know everything!