Using React Native with Expo: Pros, Cons, and Best Practices

Expo is a set of tools and services built around React Native that simplifies the development process, allowing developers to build native apps using JavaScript and React without dealing with native code. It includes Expo SDK for device API access (camera, location, notifications), Expo CLI for building and running apps, and Expo Go for instant on-device testing.

Advantages: Simplified setup with quick start and no native SDK installation required; rich API access to device features through JavaScript; over-the-air (OTA) updates that push changes directly to users without app store approvals; and cross-platform universal app development with a single codebase for iOS, Android, and web.

Limited Native Module Support: Custom native modules cannot be added unless you eject from the managed workflow, constraining advanced customization for apps requiring deep native integration.

Larger App Size: Expo bundles all available APIs into the app, resulting in larger binary sizes compared to pure React Native builds that only include necessary dependencies.

Ejection Complexity: Transitioning from Expo's managed workflow to the bare workflow can be complicated, requiring developers to configure native build tools and manage platform-specific code manually.

Choose the Right Workflow: Use the managed workflow for simplicity when your app doesn't require custom native modules. Switch to the bare workflow when you need full control over native code and custom modules.

Keep Dependencies Updated: Regularly update the Expo SDK and related packages to benefit from new features, bug fixes, and security patches. Optimize Assets: Use expo-asset to efficiently manage images and other assets for better performance.

Use Expo's Build Service: Leverage Expo's cloud build service (EAS Build) to compile your app without local build environment setup. MetaDesign Solutions offers consultation on whether Expo is the right choice, development using Expo best practices, migration assistance for ejecting when necessary, and performance optimization within the Expo ecosystem.

EAS Build: Expo Application Services (EAS) provides cloud-based build infrastructure that compiles your app for iOS and Android without requiring local Xcode or Android Studio installations. Configure build profiles in eas.json for development, preview, and production builds — each with different signing credentials, environment variables, and optimization levels.

EAS Submit and Update: eas submit automates App Store and Google Play submissions directly from the CLI. eas update enables over-the-air JavaScript bundle updates that bypass app store review cycles — deploy critical bug fixes to users within minutes. Set up update channels (production, staging) and branch-based deployments for safe rollouts with instant rollback capability.

Config Plugins: Expo config plugins bridge the gap between managed and bare workflows. They modify native project files (Info.plist, AndroidManifest.xml, build.gradle) at build time without ejecting. Create custom plugins in app.config.js to add permissions, configure deep linking schemes, set up push notification services, or integrate native SDKs.

Prebuild System: Run npx expo prebuild to generate native iOS and Android project directories from your config. This enables full native customization while still benefiting from Expo's managed tooling. The generated projects can be version-controlled and modified directly, giving teams the best of both workflows — Expo's developer experience with native-level control.

Creating Native Modules: The Expo Modules API lets you write custom native modules in Swift (iOS) and Kotlin (Android) that integrate seamlessly with Expo's managed workflow — no ejection required. Define module interfaces using TypeScript, implement platform-specific logic, and expose methods to JavaScript through a type-safe bridge.

When to Use: Build custom modules when you need functionality not covered by Expo SDK — hardware-specific integrations, proprietary SDKs, or performance-critical native operations. The Modules API supports synchronous and asynchronous methods, event emitters for real-time data streaming, and view components for embedding native UI elements. This eliminates the historical limitation of Expo requiring ejection for custom native code.

Bundle Size Reduction: Use expo-optimize to compress images and assets automatically. Enable Hermes JavaScript engine for faster startup times and reduced memory usage — Hermes is now the default engine for Expo projects. Configure Metro bundler settings to enable tree-shaking and dead code elimination for production builds.

Runtime Performance: Implement lazy loading with React.lazy() and Suspense for screens not needed at startup. Use expo-image instead of the standard Image component for aggressive caching, progressive loading, and memory-efficient image rendering. Profile performance using React DevTools and Flipper integration, identifying re-renders with the React Profiler and monitoring bridge traffic for bottlenecks.

Testing Strategy: Use Jest with @testing-library/react-native for component testing, Detox for end-to-end testing on real devices, and expo-dev-client for development builds that support debugging tools. Write integration tests that verify navigation flows, API interactions, and device feature access.

CI/CD Pipeline: Integrate EAS Build into GitHub Actions, GitLab CI, or Bitbucket Pipelines for automated builds on every push. Configure preview builds that generate QR codes for stakeholder testing. Set up automated eas update deployments for staging branches and manual approval gates for production OTA updates. Monitor update adoption rates through EAS Insights to ensure rollouts reach your user base.