It was a positive experience overall, everything was well explained on the website and you are regularly updated by email (even if they decide not to take your application further). After I was contacted on LinkedIn by a recruiter, I completed the online application and passed the online tests, then I did a phone interview. Then if you get recommended by the recruiting company, the actual HR team reviews your application (that's the furthest I got), then if you get it you go to the assessment day where they meet you face to face (more info on their website).
The only "negative" thing about this process was: when the recruitment company sent me an email to confirm my interview, they specified that the interview was going to be in English only. I was aware that being bilingual (English/French) was a requirement to apply (and I am bilingual) but they didn't specify that this specific interview was going to be in both English and French. I thought there was going to be another one in French. It wasn't that bad of an experience, I managed to do well but it would have been helpful to know ahead of time so I can at least prepare for my interview in both languages.