@surma.dev - Surma

05 Mar 2026 19:44 +0000

`builtins.wasm` is now a (experimental) thing in @determinate.systems’ nix, with a PR open for upstream nix. This lets you extend the nix language by compiling C/C++/Rust/etc into safely sandboxed, platform-independent plugins! https://determinate.systems/blog/builtins-wasm/

16 Oct 2025 16:20 +0000

I have been working on the nix & Rust codebase that builds Shopify’s monorepo, and there’s so much left to do that we need help. If you are interested, apply here to join us! DM me if you have questions! https://www.shopify.com/careers/software-engineer-monorepo-systems-rust-nix_95aac134-c21a-456d-b8b3-a9aac6aa6118

09 Sep 2025 09:45 +0000

You know your JS13k submission is going well when you have to resort to `btoa` and other seemingly stupid hacks to get below the file size limit.

04 Sep 2025 14:44 +0000

Nix friends: How terrible is this idea? I added `builtins.runWasm` to nix, allowing you to call out to Wasm. The Wasm is reset every time, so the functions remain pure. This gives you a (performant?) escape hatch for things that Nix is missing. E.g parsing YAML (here: via Rust)

10 Jul 2025 13:40 +0000

Convince me I am wrong: This should not be a type error, right? - I asserted it’s an object - I am using `?.` for property access www.typescriptlang.org/play/#code/G...

17 Jun 2025 16:19 +0000

📝 First blog in a long time! I always like “flow-based” programming, and it’s a very powerful paradigm. LangGraph lets you codify complex workflows as graphs, and also integrates really well with LangChain, if your workflow is LLM-driven. https://surma.dev/things/langgraph/

28 Mar 2025 11:01 +0000

Unexpected dangers of vibe coding: Somehow git ended up tracking its own .git folder and now I can't commit anymore :3

20 Jan 2025 11:55 +0000

Folks who know their way around the TypeScript type checker, I need help: https://gist.github.com/surma/be14ca81065bf227cee785870ee8a993 How do I figure out what types the type parameters have been bound to given a `CallExpression`? I know the answer is in `resolvedSignature.mapper`, but that’s not a public API.

18 Jan 2025 13:46 +0000

Wait, am I dumb? What does NodeJS' WASI implementation only accept file descriptor numbers for stdio? Why don't they allow a Readables/Writables? How are you supposed to capture the output of a WASI module? https://nodejs.org/api/wasi.html#new-wasioptions

16 Dec 2024 13:25 +0000

I apologize for splitting the last OTMT episode into two parts. It was sincerely unplanned. 🎧 Part II of the TC39 Drama 🌶️ Roundup is now out! In this one, I talk to @jakearchibald.com about JS0, which proposes to split JavaScript into two specifications. https://offthemainthread.tech/episode/tc39-js0-and-jssugar/

16 Dec 2024 13:25 +0000

03 Dec 2024 14:11 +0000

🎧 A brand-new OTMT episode should be in your podcast players by now: The TC39 Roundup 🌶️ Drama Edition — Part I I talk to @jakearchibald.com about the TC39 Structs proposal and how it is a big step towards shared-data multithreading in JS. https://offthemainthread.tech/episode/tc39-shared-structs/

29 Oct 2024 15:57 +0000

Get your 👂ears ready for a brand new OTMT episode! A while ago we talked about Bazel, and now it's time to take a closer look at Nix! How does it work? Is it any good for web development? In this episode, @jakearchibald.com and I try to provide answers. offthemainthread.tech/episode/nix/ https://offthemainthread.tech/episode/nix/

26 Oct 2024 15:23 +0000

I love what keybr.com thinks Rust code looks like

21 Oct 2024 10:57 +0000

ICYMI: In the latest episode of OTMT @jakearchibald.com told me all about the new, completely stylable