I applied online. The process took 2 months. I interviewed at ZS Associates (Düsseldorf) in May 2019
Interview
I applied online and then did a skype call. The interviewer was nice and patient and there weren't many difficult questions. However, they didn't get back to me at the promised time and I had to ask about the outcomings myself after a while. It felt like they wanted to ghost me more or less.