I was contacted directly by one of the CEOs to set up an interview at their HQ.
Initially I had 1h with the head of the unit I was applying to. The process was semi-formal, with questions directed more towards my project management experience, my work ethics, my business experience and my outlook
Then I had another 1h meeting with the members of the unit. They asked mostly about my previous work experiences and I had the chance to ask a few questions
Then I had a brief lunch with the CEO, we talked mostly about career and salary expectations
The whole process lasted about half a day, during which I met most of the key members of the unit I was applying to. It was a mix of formal and informal