I applied to the company in the last week of March. Initially I just gave a telephonic interview which was fairly easy. He didn't ask me anything technical but he was really impressed with my background and invited me for an onsite interview straight away. However, I had an offer so I had to cancel the interview. But things changed, and I contacted the HR again and she was nice enough to re-initiate the process. So, I gave the telephonic interview and again, not a lot of questions were asked and was called for an onsite immediately. In the onsite interview, I was introduced with the manager at first, and I could see that he had a really good tech background and was asking me questions related to machine learning and how to optimize the algorithm and the entire application. Later, I met the director (I believe), I could see that he was not really interested. He asked if I could revamp a website written in German, which was very straightforward to be honest, and I told him, yeah, it's pretty easy to do it. We talked about other stuff as well, but nothing really important. Then, I had my first and only technical interview with the person I spoke with on the phone initially. He asked me to write a program in Python (sorry, its been a while, so I don't remember the question now). My code was much more efficient than the code he had (he actually said that) and that moment, I thought I have the job.
A few days later, I got a call from the HR, she wanted to know what kind of money I'm looking for and I feel that was the deal breaker for them. Simon-Kucher doesn't pay you well, so beware of that. For a NYC job you want something around six digits to survive and with the level of experience I have and the money they were offering, I don't think I'm missed out on a good opportunity.
Good luck!