App.js Conf ‘24

Getting the most out of Expo Development Builds

You’re probably already heard of “Development Builds” - it’s the workflow you need to adopt in order to use any native functionality outside of the built-in APIs in the Expo Go Sandbox. From SDK 51 onwards, each new version of Expo Go will only support the latest Expo SDK. This makes it all the more important not to rely on Expo Go in production apps as you'd need to immediately upgrade the app to the latest SDK in order to continue developing on iPhone devices. In this talk we’ll explore why development builds are necessary as well as beneficial, the best way to get started with them, and how to leverage the built-in functionality - continuous native generation, config plugins, expo modules - to get the most out of the workflow. (edited)

Launching Desktop Apps to Orbit with React Native

In this talk, we'll talk through lessons we've learned building a macOS and Windows desktop app with React Native. We'll cover how we built native macOS modules using Expo modules, how we overcame the biggest pain points when developing for "out of tree" platforms, and how we added support for other Windows (and in the future, Linux) using react-native-web and Electron. This is the story of building Expo Orbit, a utility desktop app that accelerates your development workflow by connecting the three different environments where you interact with Expo tools and services: web, desktop, and mobile. You can click a button on the website that opens the desktop app, which in turn launches an app on a mobile device or emulator. You'll learn how we built this app in less than 3 months using the tools available today with Expo.

Bringing real-time 3D to mobile at SpaceX

Learn how Starlink is using real-time 3D to build more intuitive and engaging UI in React Native, and explore how you can bring 3D to your app.

Fetch Once, Render Everywhere: React Server Components in Expo Router

We’ve been hard at work to create a first-look at data fetching, server rendering, and streaming in universal Expo Router apps. We’ll additionally be open sourcing a new tool that we’ve used internally for reducing bundle size in our apps.

From Zero to Music Hero: Building Cross-Platform Games in Months With React Native & Skia

Discover how a single team can rapidly deploy high-performance animated apps and games across multiple platforms using React Native and Skia. This talk delves into the journey from concept to launch, highlighting the speed and efficiency of these technologies in creating engaging user experiences. Learn how to overcome the challenges of real-time feedback and smooth animations synced with audio, ensuring no lag even in the most rhythm-intensive scenarios.

Scaling Configs for Dynamic Mobile Apps

We all know how important feature flagging is and there is an abundance of services and tools available to solve this for the client-side. However, what happens when you scale beyond these off-the-shelf tools? In this talk, we will talk about how we built a remote configuration platform for the Chime React Native app to integrate with our suite of in-house feature flagging and experimentation platforms.

Brownfield integration - exploring the limits

Documentation of brownfield integration in React Native is very limited. It forces developers to reach out to X posts, outdated articles, and YouTube videos which are often ~5 years old. Moreover, they mostly focus on fundamental knowledge, forcing developers to explore the topic on themselves. However, it doesn't mean we cannot do any advanced integrations with it. During this talk, Mariusz would like to share the findings from his long brownfield journey, during which he's connected two big standalone apps. By the time of the conference it should be already available on production for ~12 million users. He's going to give some tips, and point out the most crucial problems that have appeared, and how he has solved them.

EAS Updates for Seafarers

Kadmos is probably one of the very few companies (especially in Germany!) that is using EAS Updates with the useUpdates hook on an almost daily basis. Together with maintaining our own runtime and bundle version history this allows us to deliver extremely fast and reliable to our Testing, Staging and Production apps. In my talk I want to emphasise on my experience with EAS and Expo in general with focus on the power of OTA updates via EAS. Our product is a salary and remittance tool for seafarers globally, which comes with the challenges of a big need for product stability, low network connectivity as well as broad availability in various app stores.

Don't be afraid to build a native library

Say you want an Apple Photos-style image previewer for your app. Where would you start? You might start brainstorming a complex mix of JS libraries for zooming, panning shared element transitions, pop ups and more. And weeks later, after thousands of lines of gesture logic and an imperfect solution, you'll wonder if there was a simpler way. In this talk, we'll demystify the use of native code in React Native. I'll show you how I built a beautiful image previewer in just a few hours by wrapping an existing Swift library, showing you how you could make your own. We'll explore a simpler mindset for solving complex UI problems in React Native, shifting the default from, "which JS libraries could I use" to "what is the best native implementation"?