GraphQL is a query language that is powering a lot of Facebook applications. Mobile developers at Facebook use GraphQL to describe the data they need to render their view. Server developers use GraphQL to expose the server’s data model to mobile developers. This talk will cover what it takes to connect the two worlds together, including our code generation tools that create native classes used for representing GraphQL query responses. We’ll also share some of the lessons and best practices that we learned the hard way.