Explore the intricate architecture and libraries powering Facebook's iOS applications in this 48-minute conference talk from F8 2015. Dive deep into the data layer, API design, and product models while learning about the challenges faced and solutions implemented. Discover the intricacies of immutable objects, mutation, and cold start time optimization. Examine the Model View Controllers, view hierarchy, and datastore implementation. Gain insights into multithreaded JavaScript, CSS Flexbox, and React Native integration. Understand the infrastructure framework, including basic framework decider components and performance improvements. Analyze the News Feed implementation, C components, view reuse pool, and component tree. Learn about the Year in Review feature, GitHub repo integration, and the use of C Swift in Facebook's iOS development process.