Live Dev Session: FlashList v2, Vercel AI SDK, React Compiler
Featuring
This week's livestream highlighted two major releases reshaping the React and React Native landscape: FlashList v2 and Vercel AI SDK 5. Alongside them, we covered key updates across the ecosystem, from compiler enhancements to isolated runtimes and bundler breakthroughs.
FlashList v2: A major upgrade for high-performance lists in React Native
FlashList has long been one of the most efficient list libraries available for React Native, but it wasn't without trade-offs. Developers had to estimate item sizes (estimatedItemSize or overrideItemLayout), deal with native layout patches, and work around limitations with scroll accuracy and horizontal resizing.
FlashList v2 removes those pain points while keeping its core speed and efficiency.
What's improved:
- No more estimated sizes or manual layout overrides
- Native layout correction modules removed, which means cleaner architecture
- Scroll precision is dramatically more accurate
- Horizontal lists now support dynamic item heights
It's a leaner, more predictable experience for devs, and a smoother one for users.
Vercel AI SDK 5: A stronger foundation for frontend-led AI development
Vercel continues to evolve its AI tooling with a powerful v5 release. This version strengthens the full-stack AI development experience with better abstraction, type safety, and now speech capabilities.
Key features in v5:
- Speech generation & transcription (experimental)
- Agentic loop control: New APIs like
stopWhenandprepareStepenable more controlled, multi-step workflows - Rebuilt
useChathook: Clean separation between model and UI messages, typed message streams, and more structure for streaming apps
AI SDK 5 continues to evolve rapidly, offering increasingly robust tools for building structured, type-safe AI features; especially in TypeScript-heavy environments.
Other React & React Native ecosystem updates
Vercel AI SDK workshop at React Universe Conf 2025
Matt Pocock is leading a full-day workshop on the new AI SDK v5 at React Universe (Day 0). It's hands-on, and designed for devs building production-grade AI experiences.
React Compiler nears stability
The React Compiler continues its march toward stable release. Recent updates to its documentation introduce new compiler directives like use memo and use no memo, giving developers fine-grained control over memoization and reactivity. It also now supports incremental adoption, letting teams apply compiler features selectively instead of all at once.
Next.js 15.4: Turbopack powers production
With next build --turbopack now passing all 8,298 integration tests for production builds (and powering vercel.com itself), Turbopack is no longer just for development, it's getting production-ready. This release marks a major milestone in replacing Webpack across the Next.js ecosystem.
React Native Sandbox (Callstack Incubator)
Callstack's new library enables securely isolated React Native runtimes inside a single app. Think plugin ecosystems, multi-tenant architecture, or AI agents, each running independently, with two-way messaging and crash containment.
A decade of JavaScript runtimes
From the server to the edge, and from mobile to microcontrollers, this retrospective covers how JS runtimes like Deno, Bun, Hermes, XS, and V8 expanded JavaScript into every corner of modern computing.
Catch the full replay for live demos, in-depth commentary, and dev-first takes on where React and AI development are headed next.
