Core Contributor Summit 2025 Highlights | Coffee Talk

The NFL runs on tight deadlines. Every kickoff and Super Bowl demands that millions of fans get flawless live video, stats, and fantasy features, whether they’re on iPhones, Xboxes, or connected TVs. In this episode of React Universe On Air, Mike Grabowski talks with Michael Blanchard (Director of Engineering at the NFL), about how React Native became the backbone of this high-pressure, multi-platform ecosystem. Michael shares his journey from web engineer to leading NFL’s engineering teams across nfl.com, three mobile apps, a cross-platform video player, and a suite of connected TV apps. Together with Mike, he explores the NFL’s migration strategy, the transition from Haul/Webpack to Metro and Expo, and the cultural shifts that helped merge web and native engineers into one collaborative team. You’ll learn: ➡️ Why the NFL went full Greenfield (twice) ➡️ How NFL+ shaped their second rewrite ➡️ Lessons from moving from Haul/Webpack to Metro ➡️ How Expo SDKs gradually replaced community libraries ➡️ How GitHub Actions + EAS Build reshaped their CI/CD pipeline ➡️ Strategies for handling 20–30 PRs daily in a monorepo ➡️ How React Native powers mobile, web, and multiple connected TVs ➡️ What cultural shifts enabled true cross-platform collaboration Catch more React Universe On Air episodes 🎧 https://clstk.com/4gp8Cw5 Sign up for our newsletter ✉️ https://clstk.com/4mfmRof Follow us on X 🐦 https://x.com/callstackio Chapters: 00:00 Welcome to the React Universe 01:35 Meet Michael Blanchard from NFL 03:03 NFL's digital presence and platforms 04:24 React Native in NFL's mobile apps 08:32 How React spread across all platforms 11:47 Collaboration between web and native teams 18:11 Technical decisions regarding different platforms 23:48 V2 of NFL's flagship app 25:14 Choosing migration strategy 30:10 Maintaining more product versions 34:33 Adopting Expo 42:10 Modernizing CI/CD 46:48 Team structure and workflow at NFL 53:29 Final thoughts

What really happens when React Native’s core contributors gather behind closed doors? In this episode of React Universe On Air, recorded live at React Universe Conf 2025, host Łukasz Chludziński sits down with Joel Arvidsson, Jay Meistrich, and Thibault Malbranche to unpack the hottest debates and wisest insights from the Core Contributor Summit. They dive into: ➡️ How the cooperation between consultancies, big organizations like Meta or Microsoft, and OSS contributors looks like ➡️ 2025 as the “year of stability” for React Native ➡️ The promise (and pain) of React Native for desktop apps ➡️ Flipper’s decline and new community-driven DevTools ➡️ Whether React Native 1.0 is just a marketing label or a true milestone ➡️ How agencies and individuals balance open source with client work ➡️ Practical advice for engineers who want to contribute and join the conversation Chapters: 00:00 Welcome to the React Universe 01:21 Meet our guests: Thibault Malbranche, Joel Arvidsson, Jay Meistrich 02:33 What is Core Contributor Summit 04:02 Meta vs. community usage of React Native 07:19 Year of stability & tooling challenges 09:00 Surprise session: React Native for Desktop 16:10 Concrete outcomes vs. planting seeds 21:02 Open Source dynamics & collaboration 27:30 React Native 1.0 33:45 Future directions & getting involved 36:50 Final thoughts Catch more React Universe On Air episodes 🎧 https://clstk.com/423vF9D Sign up for our newsletter ✉️ https://clstk.com/3Kb23kM Follow us on X 🐦 https://x.com/callstackio

Many React Native apps ship without full observability. The result? Blind spots in performance, crashes, and user behavior once your app is in the wild. In this episode of React Universe On Air, Łukasz Chludziński sits down with Jonathan Munz (Senior Software Engineer at Embrace) and Adam Horodyski (React Native Expert at Callstack) to unpack how OpenTelemetry can bring structure and clarity to mobile monitoring. They break down why mobile observability is harder than observability on backend, what the OTLP protocol enables, and how to instrument React Native apps without locking into a single vendor. You’ll also hear how community-driven tooling like React Native OpenTelemetry and the Embrace React Native SDK can simplify setup and improve data portability. You’ll learn: ➡️ How observability and OpenTelemetry work together ➡️ The 3 core OpenTelemetry signal types for mobile ➡️ Why mobile instrumentation is more complex than backend telemetry ➡️ How OTLP improves interoperability between tools ➡️ Where auto-instrumentation is still missing in React Native ➡️ The role of Embrace and open-source libraries in reducing setup overhead Check out episode resources on our website 📚 https://clstk.com/4104nAF Catch more React Universe On Air episodes 🎧 https://clstk.com/45EWnYe Monitor what matters in your React Native app with Callstack’s help 🤝 https://clstk.com/3HoM3KI Sign up for our newsletter ✉️ https://www.callstack.com/newsletter Follow us on X 🐦 https://x.com/callstackio Chapters 00:00 Welcome to the React Universe 01:07 Meet our guests 03:07 Defining observability and OpenTelemetry 04:32 Signals in observability 11:57 Challenges with observability in React & React Native 16:04 Standardization and OpenTelemetry protocol 18:08 Embrace and Open Telemetry 21:29 Future of OpenTelemetry in mobile 27:23 Exploring React Native OpenTelemetry 29:54 Community involvement in OpenTelemetry 37:34 Real observability in React Native 46:41 Future of React Native observability 50:40 Hey, listeners, here’s what we want you to do 54:46 Conclusion and final thoughts

What if you could skip most native builds—and still ship confidently? In this episode of React Universe On Air, we explore how the React Native Enterprise Framework (RNEF) helps large teams dramatically reduce build times and streamline development at scale. Our guest Michał Pierzchała, Principal Engineer at Callstack, shares how RNEF was built to solve real-world bottlenecks in enterprise React Native projects. Alongside him, Łukasz Chludziński discusses his experience testing the framework in a live production environment, where build times dropped from 35 minutes to just 3. What you'll learn: - How RNEF slashes native build times with CI-based caching - Ways to adopt the framework incrementally—no full rewrite required - How brownfield support lets you drop React Native into native apps easily - What makes RNEF different from Expo and Community CLI - Real-world savings and improved developer-QA workflows Check out episode resources on our website 📚 https://clstk.com/4e5OL3W Explore React Native Enterprise Framework ✨ https://clstk.com/4kAt7ap Catch more React Universe On Air episodes 🎧 https://clstk.com/3SJRk1G Get 20x faster builds on your CI in less than a week with our help 👉 https://clstk.com/3ZWJ9Tq Sign up for our New York meetup in June 2025 👉 https://clstk.com/4kEyG7C Follow us on X 🐦 https://x.com/callstackio 00:00 Welcome to the React Universe 01:07 Host & guest introductions 02:40 Project overview: React Native Enterprise Framework 04:04 Challenges in large repositories 04:50 Testing and build time optimization 07:31 Building RNEF on a real-life use case 12:37 Integrating RNEF POC to the project 15:00 Incremental adoption mindset 21:42 What it all has to do with React Native Community CLI 26:05 Optimizing build process with smart caching 44:06 Seamless collaboration between devs & QA 47:28 Brownfield projects with RNEF 55:50 Where RNEF stands in the ecosystem 59:08 What does it mean to be a React Native framework?

Is rewriting your native app really the only way to go cross-platform? In this Coffee Talk episode, we explore how React Native Brownfield offers a smarter path forward. Łukasz Chludziński invites Oskar Kwaśniewski and Burak Güner—who work directly on React Native Core and brownfield tooling—to discuss how recent advances in React Native have made brownfield integration far more viable, stable, and scalable. You’ll learn: ➡️ Why brownfield isn’t what it used to be (goodbye, brittle bridging) ➡️ How `RootViewFactory` and `ReactNativeFactory` APIs simplify setup ➡️ What’s new in React Native Brownfield 1.0.0 ➡️ How to keep your architecture clean while integrating React Native ➡️ What this means for modern native stacks like SwiftUI, Jetpack Compose—and future-facing platforms like visionOS Whether you’re maintaining a legacy app or building for what's next, this episode gives you a blueprint for hybrid success. Explore React Native Brownfield 🙌 https://github.com/callstack/react-native-brownfield Check out episode resources on our website 📚 https://bit.ly/3ESW3Lf Catch more React Universe On Air episodes 🎧 https://bit.ly/44A0q8q Get your React Universe Conf 2025 tickets 🎟 https://hubs.li/Q03l-47N0 Sign up for our newsletter ✉️ https://bit.ly/3H2xsE6 Follow us on X 🐦 https://x.com/callstackio Timestamps 00:00 Welcome to the React Universe 02:00 Meet our guests: Oskar & Burak 02:50 Let’s talk brownfield app development 03:37 Craziest brownfield setups our guests have seen 08:19 Greenfield vs. brownfield React Native 14:14 How we used to approach brownfield development 18:20 Callstack’s React Native Brownfield 23:30 RootView Factory & React Native Factory 28:50 New Features in React Native Brownfield 1.0 35:35 Sharing data between native and JavaScript 41:00 How about using different React Native versions 43:30 Cost of complexity 47:00 Learn more and get in touch with our guests

Tanner Linsley joins React Universe On Air to unpack the evolution of the TanStack ecosystem—from React Table and React Query to TanStack Router and the newest addition to the family, TanStack Start ✨ What started as internal tooling for Nozzle became a suite of libraries that shaped how developers think about server state, routing, and full-stack React apps. In this episode, Tanner shares the technical decisions behind building framework-agnostic, headless tools—and explains why client-side architecture still matters in a server-first world. You’ll also hear why TanStack Start isn’t just another full-stack framework, how React Server Components could be treated like server state, and what’s coming next for TanStack Router. If you're building React apps at scale or deciding how to modernize your frontend stack, don’t skip this one! Check out episode resources on our website 🧠 https://bit.ly/41Z876l Check out other episodes of our podcast 🎧 https://bit.ly/3XIHBeU Get your React Universe Conf 2025 tickets 🎟 https://hubs.li/Q03g5cLM0 Sign up for Callstack newsletter ✉️ https://bit.ly/4lwS7QP Follow us on X 🐦 https://twitter.com/callstackio Chapters 00:00 Welcome to the React Universe 00:00 Introduction to Open Source and Server State 01:15 Meet our guest: Tanner Linsley 02:19 How Tanner got into programming 04:06 Early programming days when there was no React yet 05:41 Cross-platform beginnings 07:40 Open Source contributions 09:24 Working on Chart.js 14:12 React Table at Nozzle 16:58 How React Static started 20:53 React Query taking shape 27:53 Community reactions to React Query 33:18 Framework agnostic approach 36:26 Cross-platform frameworks comparison 37:56 Headless, type safety, and no dependencies 46:22 TanStack Router 01:00:59 TanStack Start 01:11:06 React Server Components 01:18:51 Wrap-up 01:20:29 React Universe Conf Speakers Announcement

Ever wondered why TypeScript works so well with JavaScript libraries? It’s thanks to Definitely Typed, a project that helps developers use these libraries with type safety and autocompletion 🚀 In this Coffee Talk episode of React Universe On Air, Mike Grabowski https://x.com/grabbou chats with Boris Yankov https://x.com/borisyankov, the creator and maintainer of Definitely Typed, to uncover its story 📚 🟣 TypeScript's Beginnings: Boris revisits 2012, discussing initial challenges and contributions 🟣 Growth to Open Source Giant: From a personal project to a community powerhouse, aided by Microsoft 🟣 TypeScript vs. Flow: Discover why TypeScript thrived with robust type definitions 🟣 Functionality: How Definitely Typed integrates with NPM and TypeScript tooling 🟣 Open-Source Dynamics: Insights into collaboration without strict leadership 🟣 Top TypeScript Features: Boris and Mike's favorites, plus development tips Now, let’s hear from you! Have you ever contributed to Definitely Typed? If so, what library did you add types for and what challenges did you face? Share your experience to inspire new contributors! 🚀 Check out episode resources on our website 🧠 https://bit.ly/4jdRoSD Check out other episodes of our podcast 🎧 https://bit.ly/4hzoScR Get your React Universe Conf 2025 tickets 🎟 https://hubs.li/Q03d4Hll0 Sign up for Callstack newsletter ✉️ ​​https://bit.ly/4iVScLz Follow us on X 🐦 https://twitter.com/callstackio

Eighteen TV platforms, one codebase—what could possibly go wrong? Tune in to find out how to tackle the technical and UX challenges of building for Android TV, Apple TV, Fire TV, Tizen, and more—all with React Native! In the 49th episode of React Universe On Air, Łukasz Chludziński (https://x.com/lukasz_app) teams up with Michael Khirallah (https://x.com/mkralla11), Senior Director of Engineering at DIRECTV, and Chris Trag (https://x.com/chris_trag), Developer Evangelist at Amazon, to discuss why cross-platform development is not just a time-saver but also a way to deliver a consistent user experience. You know that at Callstack, we’re all about performance—and with devices like Samsung’s Tizen TVs released in 2017 (running Chromium 47!), performance is a serious concern. That’s why we asked our guests to share real-world techniques for optimizing TV apps, from architectural choices to strategies that avoid unnecessary performance hits on newer devices. The complexity of TV app development doesn’t stop at coding, though. Our host and guests know it all to well, so they couldn’t help but discuss how they balance unit, integration, automation, and manual testing, leveraging tools like AWS Device Farm and custom-built frameworks to ensure stability across all supported platforms. What’s in it for you? Tips on automating QA without compromising thoroughness and why manual testing remains crucial for end-user experience. Want to get started with React Native TV app development? Download our guide 📖https://hubs.li/Q038xx4l0 Check out episode resources on our website 🧠 https://hubs.li/Q038xx3k0 Check out other episodes of our podcast 🎧 https://hubs.li/Q038kRpf0 Become a speaker at React Universe Conf 2025 🎟 https://sessionize.com/react-universe-conf-2025/ Sign up for Callstack newsletters ✉️ https://hubs.li/Q038kRnp0 Follow us on X 🐦 https://twitter.com/callstackio

Reanimated 4 is here to change the way we build animations in React Native. With CSS-style animations and transitions, animations are now easier to write, more predictable, and work more like they do on the web. In this episode, Ola Desmurs-Linczewska (https://x.com/p_syche_) sits down with Tomasz Zawadzki (https://x.com/tomekzaw_) and Mateusz Łopaciński (https://x.com/MatiPl01) from Software Mansion to discuss what’s new in Reanimated 4, why React Native is moving toward web standards, and what these changes mean for developers. We talk about: 💜 Why Reanimated 4?—the motivation behind CSS-based animations and what problems they solve. 💜 How CSS animations & transitions work in React Native—use the syntax you already know! 💜 New Architecture-only support—why the old architecture is gone and what it means for migration. 💜 Aligning React Native with web standards—how Meta and the community are making React Native more like the web. 💜 Modularity and the future of Reanimated—splitting the library into smaller packages for better maintainability. 💜 Migration tips and developer experiments—how to upgrade, test new features, and start using CSS animations today. Reanimated 4 is in beta now, so experiment with it and share your impressions in the comments! Check out episode resources on our website 🧠 https://hubs.li/Q036Kc1k0 Share your feedback on this episode ✨ https://bit.ly/fdbck48 Become a speaker at React Universe Conf 2025 🎟 https://sessionize.com/react-universe-conf-2025/ Check out other episodes of our podcast 🎧 https://hubs.li/Q036KbNK0 Sign up for Callstack newsletters ✉️ https://hubs.li/Q036KbNW0 Follow us on X 🐦 https://twitter.com/callstackio

Picture this: your teams are innovating independently, deploying updates swiftly, and navigating complex app architectures with ease. Microfrontends make this possible, much like microservices revolutionized backend development. But what about mobile? How can this approach transform your app development strategy? To explore these questions, we’re joined by Zack Chapple (https://x.com/Zackary_Chapple ), Co-founder and CEO of Zephyr Cloud, and Jakub Romańczyk (https://x.com/_jbroma ), maintainer of Re.Pack at Callstack. They dive into the evolution of microfrontends, starting with the fundamentals: what they are, why they matter, and how technologies like Module Federation enable them. Zack shares insights on tools like Webpack, Rspack, and Zephyr Cloud, showing how they streamline managing complex frontends. The episode then shifts focus to mobile, where Zack and Jakub break down the Zephyr Cloud and Re.Pack collaboration. Learn how to tackle platform-specific challenges like managing version compatibility, over-the-air updates, and reducing bundle sizes—all while staying app store compliant. Plus, hear about real-world scenarios, like dynamically loading features or ejecting unused code to optimize performance, and get a sneak peek at Re.Pack 5. Check out episode resources on our website 🧠 https://hubs.li/Q034233Q0 Check out other episodes of our podcast 🎧 https://hubs.li/Q034237L0 Get your React Universe Conf 2025 tickets 🎟 https://hubs.li/Q03423Hs0 Sign up for Callstack newsletters ✉️ https://hubs.li/Q034235v0 Follow us on X 🐦 https://twitter.com/callstackio