I was contacted first via phone from their Human Resources HQ in Berlin, then I proceeded with an interview on spot. I was the only person present and I was interviewed by the Team Leader from the department I applied for. The questions were pretty easy. The only difference is that it emerged the position involved sales and cold calling, which was not specified at the beginning.
I got called to the second step of the interview (a "role game" with local HR), but I wasn't interested and at the same time I got another job.