Had to take extensive personality, math, and verbal/logic tests online before the first round interview. Attended a company presentation/reception for preselects the night before the interview. The first round interview was a case interview focusing on analytics but mostly just simple math (weighted average etc.). The second round interview happened at the headquarters in Mclean. It consisted of 4 actual interviews overall. 1 behavioral and 3 cases (1 case interview came at the end after lunch and not everyone took part in it). There was also a followup math test on-site to make sure you did not have someone else take the test for you. Pretty easy overall. The cases were harder than they actually should have been due to the pressure of the interview environment. Overall, friendly people. Got an offer and accepted it.