I was contacted via email by a recruiter from Apple to determine if I was interested in a position that the company was trying to fill at their corporate office. The interview process consisted of the following: (1) phone screen with the recruiter, (2) phone screen with the hiring manager, (3) an invitation to come onsite to Cupertino and interview.
The onsite interview is an all day event (9am - 4pm) that consisted of roughly 7 panel interviews with the hiring manager, HR, potential colleagues, Directors, and a case study presentation (there is no right or wrong answer but it's designed to see how you think and handle criticisms of your answer/choice). Also, cultural fit is extremely important at Apple as everyone believes whole heartedly in the mission.
Although I didn't get offered the role, this was by far the most professional and interesting interview experience that I've ever had. Everyone that I've interviewed with was kind and offered tips along the way to assist with subsequent interviews.