Thorough. For someone who has been in 2 previous roles in recruitment, it gave me the best possible understanding of the business, especially around culture and way or working.
I spoke with the operations team first (telephone), then line manager (facetime), then a series of on sites - 1st meeting the director, then 4 x half an hour sessions with 2 new people in each session, followed by a presentation to the business.
It sounds tough and thorough, which in some respects it is, but by the end of the process, I had met about half of the business, and vice versa. You get a sense of whether it is right for you, as opposed to jumping into the unknown.
After all, if an interview process is 'easy', what does that tell you about working there? DP make sure that their process is exhaustive, because they do not have a 'hire and fire / revolving door' business. They look after the people they hire and help them succeed.