React Native · Mobile UI at native speed

What is React Native's new architecture?

Hardnew architecturefabricturbomodulesUpdated Oct 2026

Short answer

The new architecture replaces the bridge with JSI, uses Fabric for rendering and TurboModules for native modules, and generates typed glue code. It enables synchronous measurement, lazy modules and React concurrent features.

The new architecture is a set of changes rather than one feature. JSI provides a direct C++ interface to JavaScript. Fabric is the new renderer built on an immutable shadow tree. TurboModules replace legacy native modules with lazy, typed loading. Codegen generates the interfaces between JavaScript and native.

What changes for app developers

Native modules are defined by a TypeScript spec and generated glue
Layout can be measured synchronously, which helps lists and layout-dependent logic
Concurrent React features can interrupt and prioritise rendering work
Modules load lazily, reducing startup and memory overhead
Bridgeless mode removes the legacy bridge entirely

json

{
  "codegenConfig": {
    "name": "AppSpecs",
    "type": "modules",
    "jsSrcsDir": "specs",
    "android": { "javaPackageName": "com.example.specs" }
  }
}

codegenConfig points the build at the TypeScript specs for native modules.

Migration is mostly about dependencies. Most popular libraries now support the new architecture, but older or unmaintained native modules may rely on the bridge. The interop layer can keep some legacy modules working, but it does not give them the performance or typing benefits of a rewritten module.

Test the new architecture with a release build on both platforms. Some issues only appear under the new renderer or bridgeless mode, especially around native view lifecycle and third-party SDKs.

Follow-ups you should expect

Interviewers use these to check whether the first answer was understanding or memorisation.

1What is the difference between Fabric and the old renderer?
2How does codegen work?
3What is bridgeless mode?
4How do you migrate a legacy native module?

Say it in the interview

The new architecture replaces the async bridge with JSI and adds Fabric for rendering and TurboModules for native modules, with codegen producing typed glue. The practical benefits are synchronous layout measurement, lazy module loading and support for concurrent React. Migration is mostly a dependency audit, and I test release builds on both platforms because legacy native modules can behave differently under the new renderer.

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What changes for app developers

Follow-ups you should expect

Related questions

Now say it out loud.