Recommender Systems in Industry: A Netflix Case Study

The Netflix Prize put a spotlight on the importance and use of recommender systems in real-world applications. Many the competition provided many lessons about how to approach recommendation and many more have been learned since the Grand Prize was awarded in 2009. The evolution of industrial applications of recommender systems has been driven by the availability of different kinds of user data and the level of interest for the area within the research community. The goal of this chapter is to give an up-to-date overview of recommender systems techniques used in an industrial setting. We will give a high-level description the practical use of recommendation and personalization techniques. We will highlight some of the main lessons learned from the Netflix Prize. We will then use Netflix personalization as a case study to describe several approaches and techniques used in a real-world recommendation system. Finally, we will pinpoint what we see as some promising current research avenues and unsolved problems that deserve attention in this domain from an industry perspective.