Fairly informal, with a comprehensive introduction from the President, and then an 'in-field work-interview' interview the following day, followed by the third round interview with the President upon returning to the office.
All interviews were conducted in a way that made me feel happy and relaxed, and everyone clearly wanted to create an ambience whereby both of us could interchange freely as the conversation and working day flowed, and the topics (e.g. company ethics, vision, job expectations) unfolded. The goal was for the first and second round interviews to work through the more technical aspects of my interaction related to the job itself, and for the third round to get an overall feel for my character i.e. how I would fit in with the company.