The interview in a "recruitingtag" is a long process of a Company presentation by one of the founders, then two interviews with different people and then a company tour. It takes about 4 hours in Frankfurt, and when you don't live in the city, then is a whole day on it.
If you have the chance to do the interview via Skype first, then do that.
The questions where a little all over the place. It was a interview for a specific group and it was held in English. Wich it's ok, but it's not what the job was about.
There were a lot of questions about personality and attitud, and at the end it's what makes the difference and not the qualification for the job.
They're looking for people with ideas but who won't push them. They're looking for people that can "be told" what to do, instead of reaching the creative and analytical side of your own point of view as a new member of a team.
On the day of the interview there were a group of people applying for a few jobs, and most of those people felt like it was very long and tiring process. Even the workers of the company mentioned that it was a long process and that "everyone went through the same thing" but that it is exhausting.