--- title: "Brownfield" description: "Integrating React Native into existing iOS and Android applications" url: https://www.callstack.com/insights/brownfield-react-native updated: 2026-10-22T13:55:50.377Z --- # Brownfield Integrating React Native into existing iOS and Android applications Brownfield development represents the journey of gradually adopting React Native within established native mobile applications. Discover strategies, best practices, and real-world examples of successful brownfield migrations that allow teams to leverage React Native while preserving existing native investments. ## Articles, podcasts, events and case studies - [React Native Brownfield Deep Dive: How RN Moves Into Native Applications](https://www.callstack.com/events/react-native-brownfield-deep-dive-how-rn-moves-into-native-applications) (Event, 10/9/2026): Artur Morys-Magiera will explain how React Native can move into an existing native app without forcing a big-bang rewrite. - [A brownfield architecture that kept feature delivery moving across financial apps used by millions](https://www.callstack.com/case-studies/modernizing-mobile-apps-in-production-with-react-native-and-self-hosted-ota) (Case Study, 9/4/2026): 4x increase in RN pages across the tracked page set - [React Native in .NET MAUI: A Practical Brownfield Integration Guide](https://www.callstack.com/blog/react-native-in-net-maui-a-practical-brownfield-integration-guide) (Article, 8/27/2026): Learn how to embed React Native inside a .NET MAUI app with a brownfield setup. This guide covers runtime packaging, lifecycle wiring, navigation, and shared state across both runtimes. - [Adoption of Brownfield in React Native](https://www.callstack.com/events/adoption-of-brownfield-in-react-native) (Event, 8/27/2026): Artur Morys-Magiera will explain how teams can adopt React Native incrementally inside existing native applications. - [Migration to React Native in 2026 Starts With a Delivery Question](https://www.callstack.com/blog/migration-to-react-native-in-2026-starts-with-a-delivery-question) (Article, 8/3/2026): Choosing between brownfield and greenfield React Native migration? Learn where risk sits, when to use a checkpoint, and what to prove before committing. - [How we made Hybrid iOS apps compile 39% faster with React Native Brownfield](https://www.callstack.com/blog/how-we-made-hybrid-ios-apps-compile-39-faster-with-react-native-brownfield) (Article, 7/8/2026): See how React Native Brownfield uses iOS prebuilts to cut packaging times by up to 39% for hybrid apps, with details on setup, internals, and benchmark results. - [How We Made the Brownfield Gradle Plugin 22% Faster](https://www.callstack.com/blog/how-we-made-the-brownfield-gradle-plugin-22-faster) (Article, 6/18/2026): See how task-driven Gradle optimization made the Brownfield Gradle Plugin 22% faster for clean Android release builds. - [AI-Supported Brownfield Migration to React Native](https://www.callstack.com/blog/ai-supported-brownfield-migration-to-react-native) (Article, 6/3/2026): See how AI-supported workflows cut brownfield React Native evaluation from weeks to days by speeding up setup, planning, implementation, and QA. - [Unlocking Expo Updates in an Isolated Brownfield Architecture with SDK 55](https://www.callstack.com/blog/unlocking-expo-updates-in-an-isolated-brownfield-architecture-with-sdk-55) (Article, 5/18/2026): Learn how to enable Expo Updates in an Isolated Brownfield setup with Expo SDK 55, including iOS packaging, Android patching, and OTA testing. - [State of Brownfield in React Native](https://www.callstack.com/events/state-of-brownfield-in-react-native) (Event, 4/23/2026): A practical look at Brownfield React Native adoption in mature native apps, architecture, tooling, and real-world tradeoffs. - [AI-Assisted Migrations to React Native: From Months to Days](https://www.callstack.com/events/ai-assisted-migrations-to-react-native-from-months-to-days) (Webinar, 4/2/2026): Reduce migration time from months to days by using AI in real React Native workflows. Learn when to migrate incrementally and when starting fresh is the better option. - [Brownie: A Type-Safe Shared-State Workflow for Brownfield React Native](https://www.callstack.com/blog/brownie-a-type-safe-shared-state-workflow-for-brownfield-react-native) (Article, 3/31/2026): Brownie brings stable, cross-platform shared state to brownfield React Native apps with typed models for Swift and Kotlin. - [From Brownfield Complexity to AI-Supported React Native Migration ](https://www.callstack.com/blog/from-brownfield-complexity-to-ai-supported-react-native-migration) (Article, 3/24/2026): Explore a structured, AI-supported approach to adding React Native to native apps without breaking startup or packaging flows. - [Handling Navigation in React Native Brownfield Apps](https://www.callstack.com/blog/handling-navigation-in-react-native-brownfield-apps) (Article, 3/13/2026): Learn how to connect React Native and native navigation using a typed bridge with @callstack/brownfield-navigation. - [Announcing: React Native Brownfield v3 with Expo Config Plugin](https://www.callstack.com/blog/announcing-react-native-brownfield-v3-with-expo-config-plugin) (Article, 2/26/2026): Use React Native Brownfield v3 and Expo to migrate native apps incrementally with artifact-based integration for iOS and Android. - [Introducing Brownie: Type-Safe Shared State for React Native Brownfield Apps](https://www.callstack.com/blog/introducing-brownie-type-safe-shared-state-for-react-native-brownfield-apps) (Article, 1/20/2026): A type-safe shared state library for React Native brownfield apps. Brownie syncs native and React state from a single TypeScript schema. - [Vega Developer Meetup](https://www.callstack.com/events/vega-developer-meetup) (Event, 11/17/2025): Learn how to integrate React Native into Android TV apps at the Vega Developer Meetup. Workshop, roadmap, and community talks, live in Munich. - [Scaling React Native at Zalando: How Brownfield Migration Paid Off](https://www.callstack.com/events/scaling-react-native-at-zalando-lessons-from-brownfield-migration) (Webinar, 11/5/2025): Discover how Zalando scaled React Native across a massive e-commerce app, from internal buy-in to brownfield rollout, and what they learned. - [React Everywhere: Bringing React Into Native Apps](https://www.callstack.com/events/react-everywhere-bringing-react-into-native-apps) (Event, 10/8/2025): Most teams use React on the web but still rely on native code or WebViews in their mobile apps. This talk explores how React Native can replace WebViews with minimal effort, allowing React to power both web and mobile. - [React Universe Meetup, New York](https://www.callstack.com/events/react-universe-meetup-new-york-june-2025) (Event, 6/24/2025): Join us in NYC or online for React Universe Meetup: tech talks, real-world insights, and networking with React Native devs. June 24, 2025. - [Adding React Native to iOS and Android Apps Has Never Been Easier](https://www.callstack.com/events/adding-react-native-to-ios-and-android-apps-has-never-been-easier) (Webinar, 5/27/2025): Learn how to easily add React Native to your iOS and Android apps with a modern brownfield setup powered by Callstack’s open-source tooling. - [You Don’t Need a Rewrite, You Need React Native Brownfield](https://www.callstack.com/podcasts/you-dont-need-a-rewrite-you-need-react-native-brownfield) (podcast, 5/16/2025): Discover how modern React Native Brownfield integration enables cross-platform power in native apps, without rewriting from scratch. - [Powering Native Apps with React Native Brownfield](https://www.callstack.com/blog/powering-native-apps-with-react-native-brownfield) (Article, 4/28/2025): Discover how React Native Brownfield makes it easier to blend React Native features into native apps without full rewrites or heavy migrations. - [Using React Native in Existing Apps for Faster Cross-Platform Features](https://www.callstack.com/events/using-react-native-in-existing-apps-for-faster-cross-platform-features) (Webinar, 3/13/2025): Learn how to use React Native in existing apps to speed up cross-platform development without a full rewrite. Watch the expert-led webinar now. - [Lessons from Shopify's Migration to React Native with Mustafa Ali](https://www.callstack.com/podcasts/lessons-from-shopifys-migration-to-react-native-with-mustafa-ali) (podcast, 1/13/2025): Learn how Shopify's migration to React Native led to 86% code unification, reduced build times, and seamless feature parity across platforms. - [How to Upgrade React Native in a Brownfield Application](https://www.callstack.com/blog/how-to-upgrade-react-native-in-a-brownfield-application) (Article, 11/28/2024): Learn how to upgrade React Native in a brownfield app with practical tips and solutions. Ideal for complex app migrations from React Native 0.71 to 0.76. - [How to Integrate React Native With an Existing App](https://www.callstack.com/blog/how-to-integrate-react-native-with-an-existing-app) (Article, 11/25/2024): Learn how to integrate React Native into an existing mobile app with this step-by-step guide, using the Mastodon app as a testing ground. - [Why Brownfield Development With React Native Is Worth Your Attention](https://www.callstack.com/blog/brownfield-development-with-react-native) (Article, 11/18/2024): Reduce time-to-market, development cost, and move faster with features by implementing React Native with a brownfield approach. - [Simplify Your iOS Brownfield Integration With RootViewFactory](https://www.callstack.com/blog/simplify-your-ios-brownfield-integration-with-rootviewfactory) (Article, 10/1/2024): Learn how RootViewFactory streamlines brownfield integration and helps migrate existing iOS apps to React Native efficiently. - [Adding React Native to an Existing Flutter App](https://www.callstack.com/blog/adding-react-native-to-an-existing-flutter-app) (Article, 7/24/2024): Discover how to integrate React Native into an existing Flutter app, leveraging platform views and setting up on both Android and iOS. - [Migration to React Native](https://www.callstack.com/podcasts/migration-to-react-native) (podcast, 6/14/2022): The 13th episode of React Universe On Air (formerly known as The React Native Show) is fully focused on migrating from different technologies to React Native, the two most popular approaches to this process (greenfield and brownfield software development), and our state-of-the-art brownfield approach. - [Migrating React and Native Apps To React Native - Everything You Need To Know](https://www.callstack.com/blog/migration-to-react-native) (Article, 4/19/2022): Migrate seamlessly from native to React Native - greenfield, brownfield, and best practices covered! - [Brownfield Development With React Native](https://www.callstack.com/podcasts/brownfield-development-with-react-native-6) (podcast, 6/8/2021): Learn how to tackle brownfield development with React Native, explore real-world challenges, and discover the React Native Brownfield library. - [iOS Brownfield App With React Native in an Easy Way](https://www.callstack.com/blog/ios-brownfield-app-with-react-native-in-an-easy-way) (Article, 9/6/2019): Wondering how to build an iOS brownfield app with React Native? This article will guide you through the process step by step. - [Developing an Android Brownfield App With React Native in an Easy Way](https://www.callstack.com/blog/android-brownfield-app-with-react-native-in-an-easy-way) (Article, 9/6/2019): Wondering how to build an Android brownfield app with React Native? This article will guide you through the process step by step. ## Adding React Native to existing apps? We help teams introduce React Native into brownfield projects effectively. [Talk to our team](https://www.callstack.com/contact)