Tips & Tricks From The Ultimate Guide to React Native Optimization 2025

Marc Rousavy (Margelo) talks Nitro modules, native state, zero-copy data, Vision Camera, and why speed is only part of the story.

Learn how to profile React components in React Native release builds with @callstack/inspector, using an Expo app setup that requires zero native code changes.

A deep dive into how React Native handles memory when JavaScript and native code share ArrayBuffer data. Learn why async processing can break, how GC affects raw pointers, and the safe patterns for building high-performance native integrations.

Learn how to move beyond file-based audio APIs and work directly with in-memory PCM data in React Native. This guide shows how to construct WAV buffers, use JSI for zero-copy transfers, and enable real-time audio processing.

TurboModules provide a type-safe way to write native code in React Native. JSI sits underneath as a lower-level API, enabling direct interaction with the JavaScript runtime. Beyond what TurboModules expose, JSI gives you access to powerful features, such as working directly with ArrayBuffers. This article shows how to inject a custom binding step by step.

Explore how fibers enable lightweight, cooperative multitasking. This guide walks through building a simple scheduler, managing task dependencies without locks, and using Tracy to visualize performance.

Learn how to profile and optimize multithreaded apps. Discover why more threads don’t always mean faster results and how bad thread contention really is.

Learn to fix JS performance issues in React Native-from debounce bugs to Redux selectors, in this hands-on webinar with real code examples.

Discover how Expensify defines and tracks performance metrics that actually impact user experience.

Watch Callstack's webinar on React Native JS performance. Learn to fix bottlenecks, leaks & FPS issues from the 2025 Ultimate Guide authors.

Listen to Mike Grabowski talk about React Native FastIO, a collection of primitives for working with data in React Native and its performance benefits.

Even faster React Native apps? That's possible with Nitro Modules! Tune in to the conversation with their creator, Marc Rousavy.

Learn how React Native AI uses a unified provider model to switch between cloud and on-device LLMs without rewriting application logic, enabling reliable AI experiences online and offline.

Learn how on-device models in React Native can call tools, interact with external APIs, and return structured outputs you can use directly in application logic.

Learn how to run third-party on-device LLMs in React Native using MLC LLM. Choose your models, run them efficiently across platforms, and keep a unified JavaScript API with React Native AI.

Learn how to use Apple’s built-in Foundation Models in React Native apps, reduce memory usage, and enable fast, fully on-device AI with React Native AI Apple.

Learn why on-device AI matters for React Native apps, how local LLMs behave offline, and what problems React Native AI is designed to solve from day one.

Learn how to implement a React Native TurboModule on Android, from the TypeScript spec and Codegen to the Kotlin implementation and package registration.

Learn how JavaScript, native module, background, and main threads interact in React Native TurboModules, and how to use GCD queues to run async work safely in Swift.

Learn how to expose typed, immutable constants from a Swift TurboModule using Codegen, and get full end-to-end type safety between native and JavaScript.

Learn how to emit native events from a Swift TurboModule and subscribe to them in JavaScript, including proper memory management and Codegen integration.

Learn how to build a fully working TurboModule in Swift, integrate it with Codegen, and bridge it through Objective‑C inside an Expo app.