I'm not really in a position to give advice, as I did not make it to the office visit. In total, I had two phone interviews before getting a form rejection e-mail. The first was a case study, which was awkward over the phone. Not much to prepare for there. The second was a behavioral interview where they seemed to want to get a feel for how I work in teams. Not well enough, apparently.

The first round interview consisted of a phone screening with an HR representative. The second round consisted of 2 interviews, one with an OR associate and another with a manager. One of the interviews was behavioral and the second was a case interview. The final round interview consisted of 2 case interviews and 1 behavioral interview. The cases were with an OR associate and a Manager, and the behavioral interview was with a principal.