What would you say are the key differences between the first and final round interviews?

So from my perspective, the first round interviews are a little bit broader in terms of getting to know you (and of course also for you to get to know us)! Since the first round consists of a dedicated personal and case interview that is led by colleagues from different positions (ranging from senior consultant or project manager to partners), we have the chance to get to know your skills and experiences exactly across these two dimensions and use the opportunity to see if you generally fit to Roland Berger. For you, there is also the chance to get to know some potential future colleagues from all levels due to the different interviewers during the first round.
On the other side, the final round interview is conducted by a member of our management team (partner or principal) within the specific area that you are interested in when joining Roland Berger (in my case this was for the Digital Competence Center). Within these interviews, we are trying to get a better feeling of how your skills and personality would fit within the specific competence center and the future team you are working with. You will also get the opportunity to also ask more specific and detailed questions about the projects that we are doing in this area and how your role would fit into this. Additionally, our partners and principals also use the chance to talk to you about any 'weaknesses' that we observed in the first round interviews and might steer questions in that direction (e.g. about your experience or a short case). So make sure that you consider any feedback that we give you after the first interviews and show us that you improved :).

For both interview rounds my biggest advise would be to just be true to yourself and show us what you would contribute to our work and the team you will be working with :).