Yann LeCun is the Director of AI Research at , the world’s largest social networking service. Facebook’s core business is to facilitate communication among people and between people and the digital world. The technology required to support this mission is immense given the sheer scale of data involved. As of 2014, Facebook had over 1.3 billion active (with more than 150 billion connections among each other) and 829 million unique daily logins. On an average day, these users uploaded around 350 million photos, shared around 4.75 billion items, and sent around 10 billion messages. The availability of these is so large that, for the most part, Facebook’s systems only have time to look at any piece of data just once. Such activity levels bring with them a unique set of challenges: how best to make sense of and understand all the data, and how then to use this intelligence to make decisions.