I interviewed for the summer ABM position while in business school. The process was very structured - you applied online and then the recruiting team selected people for their "close" list. Interviews were on campus. First round interviews were in the morning; they would call candidates that made it to the final round during lunch and final rounds occurred in the afternoon. Offers were made the following week

The first was on campus. The second was a longer interview with behavioral and case questions. The third was more of the same with Director level individuals. They don't care as much about your answer, but more about how you arrived at your answer. Critical thinking among ambibuity is an important skill.