🦀 React’s Compiler Just Went Full Rust
Today’s Issue: There Is Life Before Main in Rust, Only Bounds, and RustWeek Talks Are Now on YouTube
Hello Rustaceans!
In this issue, we’ll look into the recent Rust rewrite of the React compiler, spotlight a project, and highlight 10 awesome links of the week.
Here’s issue 123.
MAIN NEWS
React’s Compiler Just Went Full Rust
Two things stood out for me last week: Anthropic released Claude Fable 5, its powerful new Mythos-class model that is “safe”, and React officially merged its long-awaited Rust port of the React Compiler (formerly known as React Forget).
After months of intense work, what started as an experimental research project by Joseph Savona and team is now reality.
The original TypeScript version was already cool, it automatically figures out what to memoize so you can stop wrapping your brain around dependency arrays. But scaling it across Meta’s monstrous codebase (and eventually yours) needed more speed and rock-solid reliability. So they did the smart thing: kept the exact same high-level architecture, HIR, control-flow graphs, and SSA form… and rewrote the core in Rust.
The results? 3x faster as a Babel plugin, with the core transformation logic hitting up to 10x in some cases. All 1,725 test fixtures pass, and the intermediate states match the TS version almost byte-for-byte. They rebuilt it with arena allocation and index-based data structures like proper systems engineers.
This is yet another signal that Rust is quietly eating the frontend tooling world (OXC and SWC fans, you know what’s up). Faster builds, happier devs, and less memory drama on massive codebases.
The engineering discipline here is exceptional, heavy AI use for the grunt work, but humans firmly in for architecture, review, and quality. They even kept the public API nice and pragmatic for the ecosystem.
If you’re shipping React at any real scale, you should see some performance boost on upgrade.
Now if only they could teach it to automatically fix my terrible useEffect habits.
PROJECT SPOTLIGHT 💡
Windows-rs
Windows-rs provides a comprehensive set of Rust crates for building Windows applications, from low-level API access to high-level declarative UI.
Created by Microsoft and the Rust community, it provides the building blocks needed to interact with Windows APIs directly from Rust.
Why It Stands Out
Rust-friendly Windows APIs: Access Win32, COM, and WinRT APIs through bindings that feel like Rust instead of a foreign language wrapped in curly braces.
Async Without the Pain: Bridge Windows asynchronous operations directly into Rust’s futures ecosystem without inventing your own compatibility layer.
A Crate for Nearly Everything: From graphics and animation to registry access, services, threading, and metadata generation, it covers an impressive amount of Windows territory.
Windows-rs is open-source at https://github.com/microsoft/windows-rs.
AWESOME LINKS OF THE WEEK 🔗
Rust’s program management update for May 2026 is out covering RustWeek All Hands Utrecht, project goals changes, maintainer funding, tooling reforms, Linux collaboration, overflow handling, and interviews.
The rats at Ratatui shipped v0.30.1, packing in Block shadows, filled Chart and Canvas rendering, multi-column Tables, a Fill widget, smarter cell diffing, and performance tweaks.
Niko Matsakis wrote how Rust’s proposed “only bounds” replace ?Sized, enabling flexible trait hierarchies, future extensibility, and finer-grained generic constraints.
Luca Palmieri open-sourced cheadergen, a crate that generates accurate C headers for Rust libraries that expose a C-compatible API; because manually writing FFI headers is a fun lie we all tell ourselves.
Matt Mastracci’s There Is Life Before Main in Rust, is a deep dive into Rust pre-main execution, linker sections, initialization, and unsafe zero-cost patterns enabling powerful bootstrapping before main.
Couldn’t make it to RustWeek? All 54 talks are now on YouTube. That’s several hours of content and at least three new crates you’ll want to try by the end. [video]
Scott Chacon (GitHub co-founder) shared how he used AI agents to rewrite Git in Rust, turning decades of battle-tested code into a memory-safe library that now passes 99% of Git’s test suite.
Prisma deployed Bun’s Rust rewrite to production on Prisma Compute, fixing critical memory leaks and connection pool issues in scale-to-zero workloads.
Samuel Åkesson released is-it-slop, a CLI tool that hunts for low-effort LLM code in Rust projects by flagging outdated Rust 2021 editions, resolver v2, and dependencies that have clearly been abandoned by their creators.
Manish Goregaokar wrote about Diplomat, a clever unidirectional FFI tool that lets you expose one Rust library to multiple languages (C++, JS, Dart, Kotlin, etc.) via idiomatic bindings from a single bridge.
CodeCrafters: Become a Better Rust Engineer
CodeCrafters created amazing Rust courses that push your skills beyond the basics.
You’ll have fun building real-world projects from scratch, including Git, Docker, Redis, Kafka, SQLite, Grep, BitTorrent, HTTP Server, an Interpreter, and DNS.
The courses are self-paced, so you can learn at your own speed.
Join for free and get 40% off when you upgrade. [affiliate]
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The World Cup is finally here! Which country are you cheering for?
See you next week!
John & Elley.