I applied online. The process took 3 months. I interviewed at Spotify (Stockholm, Stockholm) in Mar 2017
Interview
Initially I didn't get the part, but a few weeks later they contacted me about an internship in another project and got an interview. It roughly lasted about an hour. The interview was in English even though this was in Stockholm. Two people held the interview, one with more technical questions and one who spoke more about the role. They were really nice and helped me with the questions, they also showed me around the offices afterwards.
Interview questions [1]
Question 1
What is a prior? Over/underfitting? What is collaborative filtering? Etc. Experience with specific algorithms. Also an open-ended question about machine learnings approaches in a certain area. Experience of working in a team was also something we discussed.