Simon Willison’s Weblog

19th December 2020

How Shopify Uses WebAssembly Outside of the Browser (via) I’m fascinated by applications of WebAssembly outside the browser. As a Python programmer I’m excited to see native code libraries getting compiled to WASM in a way that lets me call them from Python code via a bridge, but the other interesting application is executing untrusted code in a sandbox.

Shopify are doing exactly that—they are building a kind-of plugin mechanism where partner code compiled to WASM runs inside their architecture using Fastly’s Lucet. The performance numbers are in the same ballpark as native code.

Also interesting: they’re recommending AssemblyScript, a TypeScript-style language designed to compile directly to WASM without needing any additional interpreter support, as required by dynamic languages such as JavaScript, Python or Ruby.