It was a 2 part interview, 3rd part would have taken place if I had mad eit further. First interview was telephonic, took place within 2 days after I applied. The team-leader himself was on line, he asked be about general questions like describe my CV, why do I want to switch to academia, how would be your typical working day at arvato. After two weeks after an email reminde I was called for a personal interview. One week before I recieved a case study to solve and present during the interview day. On the interview day I presendted the cased study followed by general discussion on machine leanring stemmed out of the presentation. Along with the team-leader a data-engineer was present who asked me questions about which kind of inputs does he need form me to make an api of the model I made. The team-leader asked questions like which other metric would be suitable for the problem, tell more about precision and recall. The interview lasted 1.5 hour, overall a good and professional impression. After 1 week got a rejection email, yet I found the team-leader a very good person and connected him on linkedin.