Hey!

It’s Michał stepping into February’s edition of this newsletter. This month was quite packed with announcements, important updates in the React Native community, and some retrospection into the year 2024. Let’s get right to it!

Community Highlights

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

• React Native Core Contributor Summit 2024 Recap—a behind-the-scenes look at the September 2024 discussions on the future of React Native, including New Architecture adoption, community-driven improvements, and what’s next for the ecosystem.
• State of React 2024—the annual survey results are out, offering insights into the latest trends, challenges, and emerging best practices in the React ecosystem—watch our breakdown here.
• State of React Native 2024—a deep dive into how developers were using React Native in 2024, covering adoption rates, tooling preferences, and key pain points. We also analyzed the results live—watch our breakdown here.
• Bolt.new—a new AI-assisted tool that turns text into fully functional Expo apps in seconds. We put it to the test in a live stream, and while it generated a lot of excitement, it also burned through quite a few tokens.
• React Native 0.78—the latest release ships with React 19, brings back console.log output in Metro dev server (opt-in with --client-logs flag), more comprehensive brownfield iOS APIs and more.
• React Native 0.79 Sneak Peek—a notable upcoming change: Android startup time will be up to 16% faster, thanks to not compressing Hermes bytecode bundle (it wasn’t memory mapped after all!).
• Nitro Views (v0.23.0)—Nitro, initially focused on native modules, now supports writing native views as well, making it an even more powerful tool for React Native developers.
• Next.js 15.2—includes updates for debugging errors (redesigned UI and more actionable), metadata, Turbopack perf, experimental View Transitions, and more.
• Lynx: A New Native Cross-Platform Framework from ByteDance—a promising alternative to Flutter and React Native, Lynx aims to provide a high-performance native development experience with full cross-platform support—check how we try it live.

Callstack Incubator Highlights

Here are the updates from our full-time open-source team that we introduced to you last month.

React Native Framework for enterprise

We’ve just announced a new React Native Framework for Enterprise apps.

It’s built around native build reuse, incremental adoption, and self-hosting at your own infra—some core challenges that we notice in Callstack’s enterprise clients from Fortune 500.

We’re seeing these companies independently coming up with solutions to the same problems. That’s why we designed our own framework to be adopted in 5 minutes for projects using the Community CLI, the tool they already use.

You can sign up for the waiting list here.

We’ve covered this topic during a live stream, and the open-source release is coming soon!

Re.Pack v5

After months of development and testing the release candidate in production environments, we’re finally ready for a stable version of Re.Pack 5. This is the biggest release to date, featuring better performance thanks to Rspack support, Module Federation 2 with type safety and familiar web APIs, smaller configuration, and ready-to-use plugins for popular libraries in the ecosystem that needed extra setup: Reanimated, NativeWind, and Expo Modules.

You can read about it in detail and check the migration steps at Re.Pack’s blog.

JavaScriptCore extraction

With Hermes being the default JS engine for most React Native apps out there for over two years, the JavaScriptCore has been extracted from core react-native as part of Lean Core JSC RFC.

In a cooperation between Callstack and Expo coordinated by the React Native team, Oskar and Kudo Chien extracted the necessary bindings for JavaScriptCore into a separate repository, and refactored the integration points so it’s easy to use for apps that see value in using JSC over Hermes (like in apps heavy in 3D or VR/MR).

Polygen

Last month, we open-sourced Polygen, our innovative WebAssembly for React Native solution. Since then, Robert released a v0.2.0 with important bug fixes and documentation, so you can play with it and not only read the source code!

You can read more about it on our blog.

DeepSeek R1 in React Native AI SDK

Szymon and Kewin were able to run DeepSeek’s R1-Qwen distillation model locally on an iPhone 13 Pro. It adds ~1 GB to the app size and occupies ~2 GB of memory. You can play with it at https://github.com/callstackincubator/ai, which brings Vercel’s AI SDK API to React Native via Universal MLC LLM Engine.

SwiftUI with React Native

Oskar wrote a comprehensive guide on exposing SwiftUI views to React Native. With lots of native views with polished interface and interactions, using SwiftUI components in a React Native app offers some interesting possibilities, like quickly integrating a paywall or a fully native Stack Navigator with just a few lines of code (after the boilerplate is set up, which you’ll find more on in the blog post).

But there's more. I didn’t lie when I said that February was busy. In addition to the content pieces mentioned above, we also released the following blog posts, podcasts, and live streams:

Blog

• How to Easily Create Native Libraries With Nitro and Turbo Modules by Burak Güner
• How to Profile Native Code in React Native Using Tracy by Mariusz Pasiński
• Giving AI The Keys to Your App: Agents Controlling UI State by Kewin Wereszczyński

React Universe On Air podcast

• React Universe On Air #48 Reanimated 4 is the Future of Smooth React Native Animations with Tomasz Zawadzki and Mateusz Łopaciński from Software Mansion’s Reanimated team
• React Universe On Air #49 Multiple TV Platforms, One Codebase: React Native TV App Development featuring Michael Khirallah, Senior Director of Engineering at DIRECTV, and Chris Trag, Head of Developer Evangelism at Amazon

Live Streams

• LynxJS: First Impressions, Live Coding & What’s Under the Hood—joined by Matt Hargett, we went through the Lynx docs and source and tried to build an app with it and style it with CSS; it was a lot of fun! For a TL;DR, check out this thread.
• State of React Native 2024 – The Results Are Live, and So Are We!—Anisha Malde, Senior Developer Advocate at Amazon, joined Łukasz and Ola to analyze every category of this survey. Here are the key takeaways.
• Building React Universe Conf App with Replit—Mike and Oskar tried both Repl.it and Bolt.new to code a new conference app (by the way, the CFP is open), and after burning millions of tokens, they fell back to Cursor.
• Create React App is Out: Exploring Alternatives & Community Proposals—CRA is now deprecated, so Łukasz and Szymon explored other options for starting web React projects, going through Vite, TanStack Router, Parcel, and Rsbuild to check the developer experience.
• State of React 2024 Breakdown—Łukasz, Ola, and Szymon took a deep dive into the long-awaited State of React survey from 2024; brace yourselves for a two-hour ride.

Coming soon

We're also cooking a few things that you should watch out for:

• The Ultimate Guide to React Native Optimization 2025: rewritten, redesigned, with a focus on performance (more guides on other topics such as deployment, testing, microfrontends, and more coming later this year)—coming to you very soon in EPUB and PDF formats. We also ordered some printed copies.
• React Native Brownfield: we’re working on a new version with New Architecture support and integrations with our New React Native Framework for Enterprise.
• Webinar on using React Native in existing apps for faster cross-platform features: Managing multiple codebases across platforms is a challenge, but React Native offers a solution. Join Mike and Burak on March 13 (5 PM CET) for an expert session on using React Native to ship features faster across platforms while keeping native performance where it matters. Book your spot now.

Meet us in Malaysia and Barcelona

In March, we’ll get to meet at two events.

The first one is the Kuala Lumpur JS Meetup (KLJS), taking place on March 25 in Kuala Lumpur, Malaysia. Our very own Kuba Romańczyk will be giving there a talk on Re.Pack 5, exploring how Rspack and Module Federation 2 unlock new possibilities for JavaScript bundling and performance. Learn more here.

The other event is WASM I/O 2025 happening on March 27-28 in Barcelona, Spain. Robert Pasiński will take the stage alongside Kræn Hansen from MongoDB to discuss Running WASM in React Native Apps—diving into the potential of WebAssembly in cross-platform development. Learn more here.

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React Universe Conf 2025: Submit your talk & meet first speakers

The Call for Speakers closes on March 31! If you have an insightful, innovative, or game-changing talk idea, now’s your chance to submit it.

We’ve also announced our first speakers: Fernando Rojo, Neil Dhar, and D. Richard Hipp will be joining us in Wrocław this September. Plus, group discounts are now available—use ‘RUC25Teams’ for 15% off when purchasing 4+ tickets.

Thank you for reading through our updates. If you enjoy this new format (or not), let us know. We’d love your feedback on how we can improve or what we can build together.

Cheers,

Michał