Applied online. Received a request for phone interview after sending an email someone in HR, about a month after applying. Phone interview was with two managers and lasted an hour. It was a pretty standard introductory interview. Two weeks later, I was invited to fly down to interview at HQ in Houston. The interviews lasted 3.5 hours and included 7 individual interviews - 5 with managers, 2 with directors. Questions ranged from resume-related, to behavioral, to industry knowledge, to case questions. Case questions involved reading and interpreting data, calculating performance metrics, and analyzing contracts. Also, the number of windows in New York City. I received the offer about two weeks after the interview.