After getting to know each other, the interview was mostly technical questions and discussions relevant to the background needed for the position and lasted for +50 minutes. They didn't ask to do a practical test.

I took part to the Auswahltage: 2 days job interview. First day: self presentation, short tour, technical exercises (in the end you have to prepare a presentation explaining how you solved them), exercise in which you show how you would interact with a client. Second day: group exercise with the other candidates, tour of the department in which you would like to work. Very nice atmosphere.