The interviewing consisted of the two stages, the initial interview was over the phone, during which I got to know my superviser and she got to know me. It was in a relaxing manner, but very informative. I presented myself and my background, while the manager introduced the company and the department. Pretty standard. Three days later I was invited to the personal interview into the main office.
The office is open-space type and i liked it immediately. During the case I met the departments lead and the associate manager, who again got to know me and gave the case study which I had 40 minutes to solve and prepare the presentation, using a chart-board.
Even though, the test may seem stressing in the beginning, there is no correct or right answer, the main point is present your way to approach tasks. So, no need to be afraid, just dig in and start with something.