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Integrate React Native with your native application

If you have an existing application, you don't have to start from scratch. You can add React Native to existing native codebase and benefit from cross-platform features immediately.

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React Native Brownfield

Why React Native

At Scale

Why you should add React Native into existing native application

Unlike most cross-platform frameworks, React Native works alongside your existing native code, letting you adopt it incrementally and keep full access to platform APIs. It’s a practical way to go cross-platform without starting over.

Incremental adoption

Add React Native to one screen, tab, or section. Expand only when needed. No need to change what already works.

Incremental adoption

Add React Native to one screen, tab, or section. Expand only when needed. No need to change what already works.

Shared codebase

Share logic, components, and infrastructure across platforms. Cut mobile effort without cutting corners.

Shared codebase

Share logic, components, and infrastructure across platforms. Cut mobile effort without cutting corners.

Reliable performance

Properly integrated React Native matches native speed for most use cases, and users won’t notice the switch.

Reliable performance

Properly integrated React Native matches native speed for most use cases, and users won’t notice the switch.

Community case study

Shopify migrated to React Native to move even faster

Shopify started their migration to React Native over five years ago with existing iOS and Android apps. While they share significant portion of the codebase, they plan to keep brownfield integration for foreseeable future.

80%

Code shared across all platforms

2M+

Lines of code removed

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See our work

COMMON CHALLENGES

What should you watch out for when integrating React Native into a native codebase?

Brownfield React Native integration gives you flexibility, but getting it right requires careful coordination between native and JavaScript environments. These are the most common issues we help teams avoid in production.

Integration complexity

Integrating React Native into a native codebase requires managing build tooling, platform configs, and collaboration between native and JS teams.

Startup time

Improper JS engine initialization can delay app launch or cause first-screen jank. Timing and thread strategy matter.

Syncing data

Native modules require knowledge of platform-specific APIs, build systems, and memory management, slowing down development without the right support.

Bundle size impact

Without stripping unused modules or lazy-loading, React Native adds binary weight, slowing cold starts and increasing memory use.

Release coordination

React Native enables shared logic, but without care teams either underuse it or overshare and compromise platform-specific UX.

Migration strategy

Teams often start small but quickly expand React Native usage. Without a clear plan, divergent patterns, or inconsistent architecture can slip through.

Expert Insight

Quickly add React Native into existing native apps with our open-source library

Embed React Native as a precompiled, platform-native dependency—using fat AARs and XCFrameworks. This makes React Native integration transparent to native teams and keeps the surface type-safe and controlled.

Package React Native as a native library (AAR/XCFramework) with your own API surface
Reuse the same instance of React Native between different components
Compatible with native navigation, modularization, and internal tooling

Check on Github

All Insights

React Native Brownfield

Hire experts to integrate React Native into your native app

Book consultation

Integrate React Native with existing native application

Whether it’s a critical bug, architectural decision, or performance bottleneck, we’ll help your team investigate, resolve, and move forward without delay, backed by deep React Native expertise.

Improve performance of existing React Native integration

Identify and fix performance issues caused by how React Native is integrated into your native app.

Ship faster with our engineers on board

Get a complete, phased migration plan tailored to your app with next steps, success criteria, and technical milestones to ensure a smooth and safe transition.

Upskill your native engineers with React Native

Train your native engineers with all React Native best practices, from component design to debugging and performance tuning, so they can take full ownership of the codebase moving forward.

PROOF OF CONCEPT

Get React Native running in your existing mobile application in a week!

Get React Native integrated, running in production, and ready to scale—without slowing down your roadmap. You’ll see how it fits into your stack, where the value is, and what it takes to expand from there.

React Native live in your app: one screen, tab, or flow
Technical plan for scaling usage across the app
Metrics to track performance, integration cost, and end-user impact

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Why leading companies work with Callstack

Meta Official Partners

We are official Meta partner for React Native, co-organizers of React Conf and hosts of React Universe Conf.

Working at scale

We know how to make React Native work at enterprise scale, both technically and organizationally.

React Native Core Contributors

We don’t just use React Native to build cross-platform apps, we help shape it for millions of developers.

Team at scale

We’re a team of 200+ engineers ready to start fast and scale with your needs.

Enterprise-friendly

We hold ISO certifications and follow strict security standards to make onboarding smooth and compliant.

Wide range of services

As a partner for your full application lifecycle, we offer a full range of services around React and React Native.

FAQs

Brownfield setups can raise a lot of technical and strategic questions. Here are answers to the ones we hear most—so you know exactly what’s involved, what it takes, and how we can help.

Do I need to rewrite any of my existing native code to use React Native?

No. React Native can be added to your existing app without rewriting what already works. We help you isolate the right entry point, like a tab, screen, or flow, and integrate it cleanly.

How long does it take to get React Native running in our app?

In most cases, we can get a basic integration running in production in under a month. This includes setup, native bridge configuration, and one working feature or screen.

What does a typical brownfield integration involve?

We tailor the content to your team’s level, ranging from fundamentals for new joiners to deep dives into performance, architecture, and custom native integrations.

Will this change how we release our mobile apps?

React Compiler applies memoization only when it’s beneficial, unlike manual useMemo or useCallback, which can sometimes degrade performance if overused. It analyzes code statically to make smarter decisions.

Can we just try it on one screen first?

Yes and that’s often the best approach. We recommend starting with a low-risk area of the app, so your team can evaluate performance and DX before scaling.

What platforms does this work with?

We tailor the content to your team’s level, ranging from fundamentals for new joiners to deep dives into performance, architecture, and custom native integrations.

Can our native team maintain this after the integration?

Absolutely. We provide handoff documentation, training, and pairing sessions to make sure your iOS and Android engineers can work confidently with React Native.

What if we’re already using React Native in part of the app?

We tailor the content to your team’s level, ranging from fundamentals for new joiners to deep dives into performance, architecture, and custom native integrations.

We don't follow best practices, we set them