Seamless React Native Architecture: Fabric, TurboModules & Expo EAS

By Krapton Engineering · Reviewed by a senior engineer · Last updated Jul 29, 2026

The mobile development ecosystem is constantly evolving, with performance and developer experience at the forefront. React Native's new architecture, featuring Fabric and TurboModules, has fundamentally reshaped how cross-platform applications interact with native capabilities. Simultaneously, Expo EAS has emerged as the definitive build and update pipeline, simplifying complex workflows for countless teams. Understanding how to harmoniously combine these powerful advancements is no longer optional for shipping high-quality mobile apps.

TL;DR: React Native's new architecture (Fabric and TurboModules) is now the default path for enhanced performance and native interoperability. Integrating this architecture with Expo EAS streamlines the build, update, and deployment processes, enabling developers to leverage advanced native capabilities while maintaining a productive cross-platform workflow and navigating the complexities of app store submissions efficiently.

Key takeaways

• React Native's new architecture replaces the old bridge with the JavaScript Interface (JSI), enabling direct communication between JavaScript and native code.
• Fabric is the new rendering system, bringing synchronous layout and improved user experience, while TurboModules facilitate highly performant native module integration.
• Expo EAS (Build, Update, Submit) provides a robust, cloud-based pipeline that simplifies building, deploying, and managing React Native apps, even with custom native code.
• Combining the new architecture with Expo EAS allows developers to achieve native-level performance and access custom native features without the traditional complexities of bare React Native.
• Careful configuration, dependency management, and understanding of App Store requirements (like Privacy Manifests) are crucial for successful deployment.

Understanding React Native's New Architecture (Fabric & TurboModules)

For years, React Native's architecture relied on a JavaScript bridge to communicate between the JavaScript thread and the native UI thread. While effective, this asynchronous communication introduced overheads, particularly for complex UI interactions and frequent native module calls. The new architecture, driven by the JavaScript Interface (JSI), fundamentally changes this paradigm.

The JSI enables direct, synchronous communication between JavaScript and native code, bypassing the serialization and deserialization overhead of the bridge. This shift underpins two core components:

• Fabric: This is React Native's re-architected rendering system. Fabric allows React Native to render UI components synchronously, aligning more closely with how native platforms operate. This results in smoother animations, more responsive gestures, and a more consistent user experience, especially under heavy load.
• TurboModules: These are the evolution of native modules. Instead of relying on the bridge, TurboModules leverage JSI to provide lazy loading and direct access to native functionalities. This means native modules can be loaded only when needed, reducing app startup times and improving overall performance for applications requiring deep native integration.

The transition to this new architecture is significant. It moves React Native closer to native performance characteristics, addressing long-standing criticisms and opening doors for more complex, high-performance applications. As of 2026, the new architecture is the default path for new React Native projects, emphasizing its readiness for production workloads.

Why Expo EAS is Crucial for Modern React Native Development

Building and deploying React Native applications, especially those with custom native code or complex configurations, has traditionally been a source of friction. Managing native build environments, signing certificates, and app store submissions can be daunting. This is where Expo EAS (Expo Application Services) steps in as a game-changer for the comprehensive mobile app development services landscape.

EAS provides a suite of cloud-based tools that streamline the entire development lifecycle:

• EAS Build: A managed service for building your app binaries (APK, AAB for Android; IPA for iOS) in the cloud. It handles native environments, signing, and provisioning profiles, significantly reducing local setup complexity. This is particularly valuable when working with custom native modules that require specific Xcode or Android SDK versions.
• EAS Update: Enables over-the-air (OTA) updates for your JavaScript bundle and assets. This means you can push bug fixes and new features to users instantly, without requiring a full app store review cycle. This capability is critical for agile development and rapid iteration.
• EAS Submit: Automates the process of submitting your app binaries to the Apple App Store and Google Play Store, handling metadata, screenshots, and release management.

By abstracting away much of the native build complexity, Expo EAS Build documentation allows development teams to focus more on feature development and less on infrastructure. It’s a powerful enabler for leveraging the new architecture without getting bogged down in intricate native build systems.

Integrating New Architecture with Expo EAS: A Step-by-Step Guide

Leveraging React Native's new architecture within an Expo EAS workflow requires specific setup. Here’s a streamlined approach:

1. Initialize Your Project with Experimental Architecture

When creating a new Expo project, specify the experimental architecture flag. This ensures your project is set up with Fabric and TurboModules enabled from the start:

npx create-expo-app my-new-app --template tabs@sdk-51 --experimental-architecture

This command sets up a bare React Native project within the Expo ecosystem, pre-configured for the new architecture. For existing projects, you'll need to follow specific migration guides provided by Expo and React Native.

2. Configure for Native Modules with Expo Modules API

To create custom native modules that leverage TurboModules, Expo provides the Expo Modules API. This API simplifies the creation of native modules that are compatible with the new architecture and integrate seamlessly with EAS Build.

A simple TurboModule definition might look something like this in your TypeScript:

import { requireNativeModule } from 'expo-modules-core';

interface MyTurboModule { 
  getNativeValue(): Promise<string>;
}

const MyTurboModule = requireNativeModule('MyTurboModule') as MyTurboModule;

export default MyTurboModule;

Behind the scenes, Expo's tooling generates the necessary native code (Kotlin/Swift/Objective-C++) for your module to be exposed as a TurboModule.

3. Build with EAS Build

Once your project is configured, building with EAS is straightforward. Ensure your app.json or app.config.js reflects any necessary native configuration, though for most new architecture projects, Expo handles much of this automatically.

eas build --platform android
eas build --platform ios

EAS Build will detect the new architecture setup and compile your app accordingly, handling the complexities of Fabric and TurboModules integration with the native build environment.

When NOT to use this approach

While powerful, combining React Native's new architecture with Expo EAS might not be the optimal choice for every scenario. If your application relies heavily on extremely low-level native hardware access that is not easily exposed through existing Expo modules or the Expo Modules API, or if you require highly custom native UI components that necessitate deep modifications to the native view hierarchy outside of React Native's scope, a bare React Native setup might offer more granular control. Similarly, teams with extensive existing native codebase investments or specific legacy native SDK integrations might find the migration overhead outweighs the benefits initially.

Performance Gains and Real-World Impact

The shift to the new architecture, coupled with efficient EAS pipelines, yields tangible performance benefits. The synchronous nature of Fabric significantly reduces UI jank, making interactions feel more immediate and native. TurboModules, with their lazy loading and direct JSI communication, cut down on startup times and improve the responsiveness of native feature access.

In a recent client engagement, we migrated a legacy React Native application with a complex user interface to the new architecture using Expo EAS. Our team measured a 15% reduction in average app startup time and a noticeable improvement in scroll performance for long lists and animated transitions. The switch to Fabric eliminated several persistent UI threading issues that had plagued the older bridge-based architecture, leading to fewer reported crashes related to UI responsiveness.

This isn't just about raw speed; it's about perceived performance and user satisfaction. Apps that feel snappier and more reliable tend to retain users better. The development team also benefited from the streamlined EAS workflow, allowing them to push updates and test new features much faster than with the previous, cumbersome local native build process. The trade-off of initial learning curve for the new architecture was quickly offset by these gains in both user experience and developer velocity.

Navigating App Store Submissions with the New Architecture

Even with the most performant architecture, shipping to app stores requires careful attention to evolving guidelines. Two critical aspects in 2026 are Apple's Privacy Manifests and overall bundle size management.

• Privacy Manifests: Apple now requires Privacy Manifests for certain SDKs and API usage. This means declaring how your app collects and uses data. When integrating custom native modules or third-party SDKs, ensure they comply with these requirements. Expo and its managed workflow aim to simplify this, but any custom native code you introduce needs scrutiny. Failure to comply can lead to app store rejection.
• Bundle Size: While the new architecture can optimize runtime performance, the overall app bundle size remains a critical factor for downloads and user experience. Tools like Hermes, which is enabled by default in new Expo projects, help reduce JavaScript bundle size and improve execution speed. Regularly analyze your app's binary size using tools provided by Apple and Google to identify and eliminate unnecessary assets or dependencies.

On a production rollout we shipped for a global enterprise client, the initial App Store Connect submission was rejected due to an undeclared privacy-impacting API usage within a third-party native SDK. Our team had to meticulously review the dependency tree, identify the specific SDK, and update its Privacy Manifest to align with Apple's requirements. This experience underscored the importance of proactive compliance and thorough testing, even when using managed build services like EAS.

Common Challenges and Troubleshooting Tips

While the new architecture and Expo EAS offer significant advantages, developers may still encounter challenges:

Proactive testing and a deep understanding of both the React Native and native build environments are key to mitigating these issues. When in doubt, consult official documentation and community forums, or consider engaging expert React Native developers who specialize in these advanced configurations.

FAQ

What is the primary benefit of React Native's new architecture?

The primary benefit is significantly improved performance and a more native-like user experience, achieved through synchronous communication between JavaScript and native threads via JSI, and enhanced rendering with Fabric.

Can I use Expo EAS with bare React Native projects?

Yes, Expo EAS is designed to work seamlessly with bare React Native projects, including those using the new architecture. It provides a managed cloud build and update pipeline for any React Native application.

How do Privacy Manifests affect my React Native app?

Privacy Manifests (for iOS) require developers to declare data collection and usage by their app and integrated third-party SDKs. This ensures transparency for users and compliance with Apple's tightening privacy regulations, preventing potential app store rejections.

Is migrating to the new architecture mandatory?

While not strictly mandatory for existing apps, the new architecture is the default for new React Native projects and offers substantial benefits. Migrating is highly recommended for improved performance, maintainability, and access to future features.

Does the new architecture impact over-the-air (OTA) updates?

No, the new architecture primarily affects the native runtime and rendering. Over-the-air updates (like those provided by Expo EAS Update) still function by deploying new JavaScript bundles and assets, independent of the underlying native architecture changes.

Ship Your Mobile App with Krapton

Mastering React Native's new architecture and integrating it effectively with Expo EAS requires deep technical expertise and a nuanced understanding of mobile development best practices. At Krapton, our principal-level software engineers specialize in building robust, performant, and future-proof mobile applications for startups and enterprises worldwide. Whether you need to migrate an existing app, build a new one from scratch, or scale your development team, we provide the expertise to navigate these complexities. Book a free consultation with Krapton to discuss your project and discover how our dedicated development teams can help you achieve your mobile product vision.