There was only 1 interview required, and it consider quite simple, they have not much questions asked. But will ask to share more about the personal experience, and background from the previous job.

Applied with recruiting agency, introductory interview going through my skills and education with a recruiting staff, position was presented as customer service with German and English, no outbound calls, first round of selection procedure is a written test with a writing exercise to check your language skills. After passing this an interview with employees follows in both languges asking about experience and free time activities, why Global Blue etc, finally you meet the HR which is also your supervisor for a personal interview, the position, bonuses, philosophy of the company is presented, a 1.5 hours observation follows, finally you decide wheather take it or leave it