I submitted my application and very quickly received an open-ended assignment to use a large data set. I was given a week to complete the assignment. I probably took ~30 hours to work on the project. Once finished I received word that I would have an interview (via skype) the following week. The first interview was very casual I just had to talk about my experience. Very quickly after the 1st interview was over I set up a 2nd interview. The next interview was more about how I would use data to solve problems specific to Spotify. My answers weren't perfect which was probably why I wasn't offered a position.