You first have a telephone interview with the head of the department in London. After he approves of your credentials, you then meet separately with 4 different people from the department. The whole process took 2 days. It was comfortable and straightforward.

First, a phone interview was conducted that was fairly brief. The next day, I met with four members of the practice one at a time. Basic, typical questions. They want you to be prepared with a lot of varied questions for each interviewer. Study the website and come up with questions based on that and skills and you won't go wrong.