After passing through the online tests and a 1:1 phone interview (competency based - very structured, I had about 4 questions and used different experiences), you will be invited to the visit day. There will be a test in the morning (3 sections - numeracy, verbal, logicial) 40 questions in 65 minutes; it will be no problem completing if you passed through the first round and have experience in simple SHL. Because it is rather easy, the benchmark is high - I reckon you need to get about 80%+ correct, as one guy was asked to leave after the tests. You will then have lunch with a graduate and it is totally informal! First round interviews will then begin, it will be between 2-3 people and largely competency based. One interviewer will lead and the other interviewer will support and ask different follow up questions. Be sure to give eye contact to both. Then you would wait in the room while the interviewers decide and HR will tell you yes/no. So I got a yes and moved to the final round that was 1 to 1. It was by someone more senior but still largely competency based though this time he innovated on the questions a little bit and did a bit of CV/personality type of interviewing through the competencies.
All of them were conducted by CBD personell so do use the opportunity to show your commercial awareness.