I believe Shopify looked into using a JS engine in WASM for front end sandboxing but ended up using a wrapper around the Shadow Realms API instead.
Re:What Happened to WebAssembly
by potsandpans on Friday January 09, 2026 @05:39PM
(#46560441)
It's not front end sandboxing. It's edge function sandboxing. And they do indeed have this in prod: https://shopify.dev/docs/apps/build/functions/programming-la...
> Shopify CLI compiles your JavaScript code using Javy, our JavaScript-to-WebAssembly toolchain.
I've actually used Javy. Kind of interesting: https://github.com/bytecodealliance/javy.
People who want to write JavaScript for backend store functionality can, and then Shopify deploys that code into containers with small IO semantics