Inital phone call with hiring manager turned into ad-hoc interview. Was asked to join a conference call the next day for a formal phone interview with all management present. Was invited to come in person for an interview one week later. The process went like this - individual interviews with all of the management, lasted half the day. Then, taken to lunch by the hiring manager, talked about non-work stuff. After lunch, group interview with all management, and presented some prior research.