After two online interviews and an online test challenge i got an invitation to Berlin office for an on-site interview. There were three sessions. First interviewer was not senior engineer, she went over my test code. She asked me to modify it in a way, i implemented. It was easy. Second interviewer was senior engineer. We talked about the structure, performance and such. It was nice. Third interviewer was not senior again! He had no idea about the industry. He did not know what tag manager and data layer is! It was very surprising. I asked him how do they tracking and a/b testing. His answer was very disappointing. After i explained how it is done in enterprise level he asked if there were any open position in my current company. :) I don't judge him. As in general the company does tracking and a/b testing in such an amateur way. They have fairly large teams because of the amateur way of them doing it. I told them and it was not welcomed.