First I got to chat with the recruiter and few days after I had my first 30 minutes interview with the hiring Manager. 8 other rounds of 30 minute interviews followed that felt a bit endless at some point but I thing it's a good approach as I got to talk to the team, to my peers and main stakeholders that gave me a really good feel of the org, of the team and some of the challenges they are facing and expectations they have towards this role.
All 9 rounds were essentially 30-45 minute conversations and I did not have to prep anything in advance.