First, I make a contact by email after I saw the announcement of the position. They asked me my CV and 2 weeks later I received an email with an invitation to the on-site interview. The interview is with the professor you are going to be working. Experience was nice. A whole day on-site interview. You talked about some particular problems (in my case a physical problem) and then they will ask you how to solve the same or a different problem. You have to think about the problem and propose a solution. Later the professor will ask you about your background and other projects you have been working. In some case, they can ask you to give a talk about your research project, but in my case, they did not. The professor invited me to go for a lunch and we spent some time talking again about science during the lunch time. Again, some question to be answered. Later I was dropped with other fellows working in the same group where I introduced myself and they asked me questions about my works and I also asked them some questions. Later in the night, other fellows picked me up for a dinner. During the dinner, we did not talk about science only about personal things, like how is the life in the city, and other things. Overall it was a good experience, one week later they sent me an offer and I accepted.