Ever wonder how Spotify’s Discover Weekly picks are so consistently good? If you want to learn exactly how they’ve mastered their playlists, it’s a little complicated. But the jist of it is, Spotify starts by looking at the 2 billion playlists that are created by users. Spotify also creates a profile of each user’s individualized taste in music, grouped into clusters of artists and micro-genres. They then attempt to fill in the blanks between your listening habits and those with similar tastes. The connection between data from 2 billion playlists and your personal taste profile is made by Spotify’s algorithms.