As first introductory call with the CTO, nothing was asked about my skills to check if my technical abilities could match the position they are filling. Instead, I was warned that I should perform beyond the full time working hours and that they expect me to handle a lot of manual tasks. Although, the part that really surprised me concerned what was the opinion I left in the previous company because they were going to contact my old managers and he even asked for the name of one of them. This is strictly illegal according to Article 6 & 7 of the GDPR. I already gathered feedback from my previous managers with both Arbeitszeugnis and also asking direct feedback in a document that my previous employer asked me. No employer can contact your old managers while asking about you because it would violate the Data Protection.