Online test (I think around 4 different stages, all the usual stuff), online interview (6 questions each given only one minute to prepare and then 5 minutes to answer), then assessment centre.
A pleasant and well-organised day, and I felt that the interviewers were considerate and attentive. Although I didn't get an offer, I thought the process was rigorous and fair. One point to note, they didn't offer to cover any of our expenses, but only invited us 10 days in advance to their office in London. Many candidates had to stay overnight as the day started so early, and accommodation prices were very high so close to the time. Given that their office shares a site with a budget hotel, you would think they would be able to negotiate a corporate rate for instances such as this.
Online application, online test, recorded video interview, maths test, assessment centre which involves a presentation and interview. The recruitment team is very helpful, especially on the day of the assessment centre.