iOS & Android Development

Lottie AirBnB: Behind the scenes of our new open-source animation tool. Lottie is an iOS, Android, and React Native library that renders After Effects animations in real time, and allows native apps to use animations as easily as they use static assets. Lottie uses animation data exported as JSON files from an open-source After Effects extension called Bodymovin. The extension is bundled with a JavaScript player that can render the animations on the web. Lottie also has several features built into its API to make it more versatile and efficient. It supports loading JSON files over the network, which is useful for A/B testing. It also has an optional caching mechanism, so frequently used animations, such as a wish-list heart, can load a cached copy each time. Lottie animations can be driven by gestures using the animated progress feature, and animation speed can be manipulated by changing a simple value. iOS even supports adding additional native UI to an animation at

RIBs is the cross-platform architecture framework behind many mobile apps at Uber. The name RIBs is short for Router, Interactor and Builder, which are core components of this architecture. This framework is designed for mobile apps with a large number of engineers and nested states. The RIBs architecture provides: Shared architecture across iOS and Android. Build cross-platform apps that have similar architecture, enabling iOS and Android teams to cross-review business logic code. Testability and Isolation. Classes must be easy to unit test and reason about in isolation. Individual RIB classes have distinct responsibilities like: routing, business, view logic, creation. Plus, most RIB logic is decoupled from child RIB logic. This makes RIB classes easy to test and reason about independently. Tooling for developer productivity. RIBs come with IDE tooling around code generation, memory leak detection, static analysis and runtime integrations - all which improve developer product