I went for a first day of 1-1 meetings with HR, my future manager and 2 future collaborators. It lasted for about 3 hours. I was asked to talk about my career so far. I also got lots of opportunities to ask questions. It was a friendly informal atmosphere. I got invited for a second round and had additional meetings with the team of architects and again with future boss and HR. I got a great impression of the company because they wanted to make sure that they hire the right person. I was also impressed with the level of expertise of the guys who interviewed me.