After an initial CV sift, you are sent a video-game style psychometric test. This was fine (fun, even) and unlike any other assessment I've done before.
Then, we were invited to take part in a 6 hour assessment centre (counting breaks for lunch and so on). This was a fairly typical ordeal with a presentation by the staff at the beginning, followed by group activities and then individual interviews. There was a noticeable "bro culture" to the whole thing but this may have just been due to the specific people they brought to the centre.
The group assessments were two team-based activities where you could define your own roles and group dynamic. They are looking out for natural leaders here so try and be confident and assert yourself.
After this, you go through about five speedy interviews, 3 minutes each, with each staff member, going through some core ideas and competencies. This part was well-run and thoughtful, and included questions about how you felt you performed in the previous activities.
We were told that we would hear back from them within a week or two, but this never happened. I wouldn't be contacted by anyone on the assessing team for a long while after the interviews.
After a month of multiple emails and calls asking for an update I was finally rejected, though I never received any feedback or tips for improvement despite specifically asking for this. I think this shows a huge lack of respect for the applicant's time and effort, and wouldn't recommend applying for this scheme unless you are very confident you'll get through.