🦀 The Great Zig-to-Rust Experiment
Today’s issue: Rolldown 1.0 Is Out, NVIDIA Open-Sourced Cuda-Oxide, and Compile-Time Chaos in Rustc
Hello, Rustaceans!
Hope you had a wonderful Mother’s Day and got to spend some quality time with the people who matter most.
In this issue, we’ll discuss the recent Bun’s rewrite experiment, share a useful Rust tip, spotlight a project, and highlight 10 awesome links of the week.
Here’s issue #118.
MAIN NEWS
The Great Zig-to-Rust Experiment
Bun, the JavaScript runtime with insane speed, and built in Zig announced one of the most fascinating public experiments in modern systems programming.
A new branch claude/phase-a-port appeared with hundreds of thousands of lines (around 966k LOC) of AI-generated Rust code sitting right next to the original Zig implementation.
It’s not quite a rewrite announcement yet but it’s a high-signal peek into the future of large-scale code migration and language trade-offs.
Jarred Sumner and the Bun team (now under Anthropic) committed a detailed Zig to Rust porting guide with roughly 300 rules.
The branch follows a two-phase approach:
Phase A (current): Faithfully translate logic file-by-file. The Rust doesn’t need to compile yet, it’s about capturing intent. AI agents (Claude-powered, with robobun PRs) are doing the heavy lifting.
Phase B: Make it build crate-by-crate and get it running.
Jarred was quick to temper expectations on Hacker News:
‘We haven’t committed to rewriting. There’s a very high chance all this code gets thrown out completely. I’m curious to see what a working version looks like, how it performs, and how it feels.’
This is classic engineering curiosity meets unlimited Anthropic tokens.
Many of us suspect Zig still holds an edge in raw throughput and memory efficiency for certain low-level runtime work (Bun has historically beaten Deno in benchmarks partly thanks to this). A side-by-side Rust version will finally give us real data instead of tribal speculation.
I love this move. Even if the Rust port ultimately gets discarded, the exercise is pure gold. It forces honest comparison on metrics that matter: performance, developer velocity, safety, onboarding, and ecosystem leverage.
I appreciate both languages, I hope Bun keeps its ruthless focus on being the fastest and most delightful JS runtime regardless of implementation language.
This isn’t the death of Zig in Bun, it’s a smart, public stress test of alternatives. Whether it leads to a hybrid future, a full pivot, or just invaluable lessons, experiments like this are why systems programming remains exciting.
I can’t wait for Phase B results and those inevitable performance numbers.
RUST TIP 🦀
Last week we shared a tip on using const generics + generic_const_exprs (nightly) for compile-time sized things. Now, onto this week’s tip.
scopeguard for Defer-Like Cleanup + Panic-Safe Guards
RAII is great, but sometimes you want ‘run this at scope exit no matter what.’
use scopeguard::defer;
{
let handle = open_thing();
defer! { close_thing(handle); }
// ...
} // guaranteed cleanupSystems use: FFI resource management, temporary mappings, tests.
PROJECT SPOTLIGHT 💡
rust-openssl
Rust-openssl is a crate providing OpenSSL bindings for the Rust programming language.
At its core, you can handle encryption, TLS, and certificates without abandoning Rust entirely.
Here’s why it earns its keep:
Safe-ish abstractions over unsafe code. You still get OpenSSL’s power, but wrapped in APIs that won’t ruin your day.
Actively maintained with frequent releases. It keeps up with OpenSSL updates so you don’t have to panic every time a CVE drops.
Battle-tested by the ecosystem. Plenty of real-world usage means fewer surprises when things go live.
Rust-openssl is available at https://github.com/rust-openssl/rust-openssl.
AWESOME LINKS OF THE WEEK 🔗
Rust joins outreachy 2026, mentoring four interns on compiler, interop, fuzzing, and security projects, expanding inclusivity beyond Google Summer of Code. In other news, march 2026 project director update is out.
Dion wrote why async Rust still bloats binaries via inefficient state machines; proposed compiler optimizations could reduce size, improve performance, especially for embedded systems.
After two years in the oven, Rolldown 1.0 is finally here. The Rust-powered JS bundler now drives Vite 8 and reportedly runs 10–30x faster than Rollup. More in the next issue.
Mathias interviewed Arya and Martin from NLnet labs about what it takes to maintain critical Internet infrastructure as a small team, and why they bet on Rust for new projects. [video]
Zellic published its Rust-Coreutils security audit report. It’s thorough, mildly terrifying, and probably longer than your weekend plans.
Jiawen Wang released charton, an altair-style declarative plotting crate for Rust.
Arya discovered macro patterns that trigger near-exponential compile-time chaos in rustc using basically just tokens. Turns out macro parsing is secretly an algorithmic horror movie.
Citi is hiring a senior low latency engineer to build ultra-fast Rust trading systems handling microsecond-level finance workloads.
NVIDIA Research open-sourced cuda-oxide, an experimental Rust-to-CUDA compiler that lets you write (SIMT) GPU kernels in idiomatic Rust.
Seattle Rust user group is hosting a meetup on 'Nine Ways to Get Inheritance in Rust' this May 21st. If you’re in the Washington area, come through and let’s talk Rust before someone tries to reinvent OOP again.
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]
X | BlueSky | Mastodon | GitHub | LinkedIn | Buy us coffee | hello@rustbytes.com
Had an awesome time with loved ones over Mother’s Day and feeling really great and energized for the week ahead.
See you next week!
John & Elley.