I applied for the Capgemini CDC (Financial Services Consulting Academy) and my application process was relatively quick and easy (although I was told the process was changing/being extended for the next interview cohort? (March 2018)) I submitted an online application, answering your typical: 'Why consulting?' 'Why Capgemini?' 'Why this particular role?' etc type questions and heard back within a week.
When I had confirmation I'd passed this stage I was sent an Online Numerical and Inductive Reasoning test (7days to compete). Again, within a week I got a phone call from a Capgemini employee who "invited" me to a phone interview with him later that week. The phone interview was straightforward - competency questions and (even though he told me to assume he hadn't read my CV) a few questions regarding my experience from roles I had previously been in. This took just over half an hour. The benefit being he was open to answer questions about his own experiences at the firm and he just so happened to work in an area I was quite interested in. Definitely worthwhile picking the interviewers brain.
The next stage was the assessment centre (3 parts to the day - the order you do them in is varied): A pre-prepared case study, a one-to-one Interview and a group exercise. Nothing to worry about. The case study has a lot of information to digest - my advice being, just go through it with a fine comb so that at least it's thoroughly understood. You only receive this a few days beforehand. My presentation was questioned/challenged a few times on the basis of my rationale but (it seemed) more so to test my knowledge of the material than to test my assessment of it.
The group exercise is exactly what it says on the tin - you work as a team to achieve a set goal. My advice, again, just make sure the task is thoroughly understood so your contributions are all relevant. Even if you speak infrequently, if everything you say adds value to the overall discussion you won't fare badly. Lastly is the mini assessment/one-to-one interview where you're given a few on the spot business scenarios to assess (not particularly difficult and you're given time to plan your answers). Again, the idea being to see how you tackle problems and whether you can decipher information the way a consultant might. This took ten or so minutes and was followed by roughly 30mins of further competency based questions, rounded off (in my case) with a question about my career aspirations in both life and with Capgem. Might be worth prepping that one just in case.
Hope this was helpful!