How Netflix Predicts Movie Tastes

The big dog of algorithms at Netflix in the early days was collaborative filtering. It basically says that because Rob likes breaking bad four stars, Rob's going to like how's the cards? Do you like it? Five stars. Now this is done at scale. The algorithm doesn't really know anything about the content of the movie,. But this algorithm worked and our problem was we only had one engineer. And what we did was we outsourced it.