This Week In React #226: Parcel, TanStack, Astro, React-Scan, React-Router | Worklets, Enterprise Framework, Perf, Expo UI, FlatList...

Hi everyone!

Cyril and Matthieu from Theodo Apps here 👋, with some big updates in React and React Native!

React Server Components are now supported in Parcel, making it a more viable bundler for modern apps. Callstack is working on a new React Native framework aimed at enterprise teams, promising better build caching. React Native Worklets is bringing real multithreading to React Native, finally decoupling it from animations. And React 19 migrations are picking up speed, with teams sharing insights on adapting to the changes.

Exciting times ahead—let’s dive in! 🚀

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⚛️ React

Parcel v2.14.0

Parcel is an interesting thing: it’s a very robust and feature-complete bundler. While not used/supported by any major React framework, it doesn’t prevent it from moving forward, with v2.14.0 adding a few big features:

Server Components with client, server, and static rendering
Integrated MDX support (using the rust lib mdx-rs)
A create-parcel CLI that can be a replacement for create-react-app
A new React error overlay

If you’re “building your own framework” or have a niche use case, all this makes parcel even more attractive.

💸 Convex launched an MCP Server
🐦 Support for streaming coming to React Query
🗓 StrapiConf - 🇫🇷 Paris - 13 May. Discover the full lineup : Shruti Kapoor, Quentin de Quelen, Sebastien Chopin! And get a 10% discount with code "TWIR”
🗓 Future Frontend - 🇫🇮 Espoo - 26-28 May. Web development/design and AI meet on a single track. Secure your spot today with a 10% discount using code "TWIR”
📣 TanStack + Netlify Partnership
📜 Live Mode: Live data updates in React with TanStack's Infinite Queries.
📜 How we migrated MUI X to React 19: They needed to maintain compatibility with React 18 even though there are a few breaking changes in React 19 (with refs and StrictMode).
📜 Writing static websites with Vite and React: The author describes how the experimental vite-ssg-react package he’s working on works, and what he plans for the future.
📜 SSR Deep Dive for React Developers: Your framework probably handles SSR for you, but you’ll learn how to implement it yourself, and how it works along the way
📜 Common React libraries architecture
📜 Why React is surprisingly the best model for LLM workflows
💸 VS Code extension: Get React component usage insights in VS Code
📦 Astro 5.5 - Type-safe sessions, better Mermaid diagrams integration
📦 React Scan 0.3 - See the parents of rendered components
📦 TanStack Form 1.1 - Form reset util
📦 React Router 7.4
🎥 Theo - Tanner just fixed forms
🎥 Epic Web Dev - Upgrading React Router
🎥 Web Dev Simplified - Next.js Finally Fixed Caching

Tests are dead - Meticulous is here

Meticulous creates and maintains an exhaustive suite of e2e ui tests with zero developer effort.

Dropbox, Bilt Rewards, Lattice and hundreds of engineering organizations rely on Meticulous for their frontend testing.

This quote from the CTO of Traba sums the product up best: "Meticulous has fundamentally changed the way we approach frontend testing in our web applications, fully eliminating the need to write any frontend tests. The software gives us confidence that every change will be completely regression tested, allowing us to ship more quickly with significantly fewer bugs in our code."

This post from our CTO, who formerly led a large engineering group at Palantir, sets out the context of why exhaustive testing can double engineering velocity.

📱 React-Native

React Native Worklets RFC

React Native Worklets is a new library extracted from Reanimated that enables true multithreading in React Native. It lets you run JavaScript code on multiple runtimes. A new memory model introduces Serializables, Shareables, and Synchronizables to handle data across runtimes.

By decoupling multithreading from animations, Reanimated becomes leaner, which is especially beneficial for web apps aiming for smaller bundle sizes. At the same time, developers can now use multithreading for non-UI tasks like async storage, database operations, real-time audio processing, or AI-powered computations — without depending on an animation library.

💸 PostHog - How to set up a React Native remote config (with Expo Router)
🐦 React Native in Native apps: strategies and blockers
🐦 React Native Bottom Tabs integrate seamlessly with other native UI elements
🐦 expo/ui will launch with Expo SDK 53: It will include fully native input components, iOS form sections, context menus and iOS previews.
🐦 React Server Functions in Expo Router
📊 RevenueCat State of Subscription Apps 2025: Cross-platform subscription apps (in particular React Native ones) have better performances in retention and monetization compared to native apps. The top-performing ones excel by optimizing onboarding, surfacing paywalls early, and leveraging hybrid monetization.
📖 Ultimate Guide to React Native Optimization 2025: Callstack just published their upgraded guide.
📖 Expo Documentation - Using push notifications: Fresh reminder on what services are available to implement push notifications in an Expo app.
📜 We’re Building a New React Native Framework: Michał from callstack unveiled features of their React Native framework targeting large mobile teams, emphasizing fast native build caching. It's still not open sourced yet.
📜 FlatList Optimization: Avoid Re-Rendering When Adding or Removing Items
📦 Expo BackgroundTask Beta
📦 Create React Native Library 0.48: Add template for Nitro modules
📦 Galeria 1.1 - Fix new architecture issues, support for edge-to-edge
🎙️ RNR 325 - Legend List with Jay Meistrich

🔀 Other

👀 Node.js TSC - Should Corepack stay in the Node.js distribution?: Corepack will stop being distributed with Node.js starting v25.
📜 Node.js Launches Official Community Space on Discord
📜 Support for CSS and Baseline has shipped in ESLint
📦 Oxc Minifier Alpha: A new minifier that already outperform esbuild and is used with Rolldown, which aims to become the next default bundler for Vite.
📦 Oxlint Beta: It features over 500 built-in linting rules with significant performance boosts, allowing small to medium projects to fully replace ESLint. ESLint plugin & custom rules support should come in the next major release.
📦 Valibot 1.0 - 1kB alternative to Zod
📦 Node.js 23.10 - New --experimental-config-file
📦 Node.js 20.19 - require(esm) enabled

🤭 Fun

See ya! 👋

This Week In React #226: Parcel, TanStack, Astro, React-Scan, React-Router | Worklets, Enterprise Framework, Perf, Expo UI, FlatList...

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