If you're building a mobile app or a client-heavy HTML/JavaScript app, there's probably data that you manipulate locally on a device and also store on a server. That means you're syncing, and syncing is hard. This talk will cover all the things you're probably NOT thinking about when rolling your own syncing engine, like offline caching, change notification, and advanced conflict resolution. Drawing from his experience at Dropbox and Microsoft, Steve will discuss the thorny challenges and potential solutions for sync.