Hey!

It’s Michał again. April was full of announcements and interesting explorations for Callstack’s R&D, React web team and React Native community. Let’s get right to the most notable updates that you definitely don’t want to miss.

Community Highlights

Before we get to Callstack updates, take a look at some key updates in the React Universe from the last month:

• React Native 0.79: 3x faster Metro startup, faster Android app startup (TTI), better Swift compatibility for native modules, removal of remote JS debugging, JSC moving to community package (which we covered in the last issue as it was done by Oskar), aliases in package.json, and more.
• Expo SDK 53: It’s finally there with React Native 0.79, React 19, edge-to-edge by default on Android, improved background tasks with expo-background-task, debug builds on TestFlight (!), faster Expo Module builds on Android, and more.
• FlashList 2.0: The rewrite of Shopify’s list to new architecture is heading to an end with the 2.0-alpha release. It doesn’t require size estimates anymore, and it’s faster.
• Legend List 1.0: Another fast, community-driven, JS-based list implementation by Jay Meistrich is now stable, with a mostly compatible API to FlatList. Time to give it a go.
• Shopify Mobile Bridge: Making WebViews Feel Native: Really neat UX considerations when working with WebView, so that the content inside feels more native. It very well aligns with our experience in this field.
• React Labs: View Transitions, Activity, and more: The React team introduces two new experimental features: View Transitions for animations and Activity for hiding/showing UI and pre-rendering at lower priority. Additional updates include features currently in development: React Performance Tracks in DevTools, Compiler IDE Extension, Automatic Effect Dependencies with React Compiler, Fragment Refs, and Concurrent Stores for libraries.

Callstack Incubator Highlights

React Native AI

There’s a new way to run large language models (LLMs) on devices and it’s called react-native-ai. It’s a new project led by Szymon and Kewin that promises offline AI capabilities  with Vercel SDK API that you probably already know from the web. You can, of course, download your favorite models from HuggingFace at runtime. Give it a try and help us explore the limits of this approach.

React Native Enterprise Framework is open-source

The time has come! Two months after announcing that we’re building a new framework, you can freely access it through NPM and GitHub, because it’s open-source. Give React Native Enterprise Framework (RNEF) a star if you like new frameworks or currently use React Native Community CLI (it takes 10 minutes to upgrade and open your project to new goodies—such as remote build cache—without much effort).

React Native Brownfield v1

The library for integrating React Native into existing iOS and Android apps,  react-native-brownfield got a huge boost from Oskar and just shipped v1 with new architecture, building on top of better and simpler API and supporting SwiftUI and Jetpack Compose. You can also use it when packaging your React Native app as a framework for improved DX, which is supported through RNEF brownfield plugins.

React Native Paper is back!

With over 200k weekly downloads, react-native-paper is one of the most used UI library in the React Native Community. For quite some time, we’ve held it in maintenance mode, without much active development. We listened to the latest feedback on the library however, went back to the drawing board, and decided it’s time to give the library a breath of fresh air, as we have some exciting ideas ahead of it. Luke is back at work fixing bugs and prepping for v6 release. Stay tuned!

Experimenting with CSS in React Native

Some say competition drives progress and innovation. And we believe in that. When Mario heard about Lynx supporting CSS, having a few attempts at rewriting Yoga already behind, he went into his favorite C++ rabbit hole to see if we could have CSS in React Native. Results? It seems we could! This is an early, but promising, experiment, and we’ll certainly explore this space in the upcoming months.

Module Federation in Metro

Jakub was clearly fed up with Module Federation being only available in Re.Pack and, guess what, he’s now working on making it available for every React Native app without migrating to different bundlers. That’s right, Metro is going to get MF support really soon! We’re excited to collaborate with the Metro core team. And kudos to Zephyr Cloud sponsoring this effort 🙌

Self-hosted over-the-air updates

With CodePush being sun set at the end of March, there’s an explosion of alternative services that want to get a piece of the OTA cake. Szymon recently gave a try to hot-updater—a self-hosted OTA tool, and it was a surprisingly pleasant experience. Moreover, the maintainer added support to RNEF the second day it was open-sourced. We’ll continue to watch this project.

Blog

Latest article on our blog

• Powering Native Apps with React Native Brownfield by Burak Güner: See React Native Brownfield v1 in action, where its new API and packaging support help add a React Native app to an existing iOS and Android project.
• Profiling React Native Internals with Tracy by Mariusz Pasiński: Another exploration of low-level C++ profiling with Tracy; this time it’s about going through React Native internals step-by-step to assess CPU usage and memory allocations using this powerful tool.

Podcast, webinars & talks

• React Universe On Air #50: Exploring TanStack Ecosystem with Tanner Linsley: From React Query to TanStack Start—Tanner Linsley walks through the evolution of TanStack’s headless libraries and explains the thinking behind full-stack client-first architecture.
• Why You Need React Native Enterprise Framework with Mike Grabowski and Michał Pierzchała: Get to know our recently open-sourced framework built for large teams and projects that helps tackle slow CI builds, complex native code, and platform fragmentation with scalable, cloud-agnostic solutions.
• Master JavaScript Performance in React Native (Part 1) with Mike Grabowski and Szymon Chmal: Learn how to spot real JS performance bottlenecks, avoid common pitfalls, and keep your UI smooth with yielding and async patterns.
• How to Make Your React (Native) App Feel Native by Oskar Kwaśniewski: From platform-specific gestures to UX nuance, get a practical breakdown of how to build apps that feel right on iOS, Android, VisionOS, and more.
• I Built a File-Based Router for React Native by Szymon Chmal: How a weekend hack led to a custom file router with dynamic imports, suspense handling, and Next.js vibes—all running natively on React Native.
• Bring Your Favorite Language to React Native by Robert Pasiński: Discover PolyGen—a WebAssembly-based toolkit for embedding Rust, Go, COBOL (yes, really) and more into React Native apps, no TurboModules required.

Coming Soon

• NodeAPI: We keep working in this area together with our tech partners and have some exciting updates to share in the upcoming months,
• OpenTelemetry: Adam is working on the react-native-open-telemetry in the open, and we’re still interested in this space. Feel free to give it a star and watch what’s coming.

REACT UNIVERSE CONF 2025 UPDATE

Big momentum on the React Universe front:

• Speaker lineup just got even stronger. Welcome Violina Popova (ClipMyHorse.TV), Vladimir Morozov & Khalef Hosany (Microsoft), Kræn Hansen (MongoDB), and Dr. Kubilay Ahmet Küçük (Oxford University).
• Diversity & Volunteer applications are now open! Want to attend or help out? Apply at reactuniverseconf.com/diversity
• Regular Access tickets are on sale—grab yours before prices go up. Group coming? Use RUC25Teams for 15% off 4+ tickets.
• Performance Workshops are selling fast. Tere are just a few seats lets, so don’t wait too long before saving your spot at reactuniverseconf.com/workshops-2025

That’s it for April’s updates. Stay tuned for what’s coming in May, because we’re already working on some events and content pieces that we couldn’t mention in this newsletter edition yet.

Cheers,

Michał