Not every checkout requirement fits a rule. When your logic goes beyond what configuration can express, our engineers design, build, test, and ship it as a native Shopify Function — end to end.
Custom checkout logic usually starts the same way: a requirement that sounds simple, until you try to build it.
We architect it properly, build it as a native Shopify Function, and hand you back a reusable Rulic configuration — so it’s never a one-off again.
We map the exact behavior you need, including edge cases, before anything is built.
A design for the Shopify Function — inputs, data sources, and failure modes — reviewed before implementation.
Production-grade Rust, compiled to WASM, built to Shopify’s checkout performance budget.
Every branch of the logic run through Rulic’s simulator before it ever touches a live checkout.
Development store first, then staging, then production — never a first deploy to a live store.
A written spec and a portable Rulic config, so the same logic deploys to your next client in minutes.
Tell us what you’re trying to build. We’ll tell you honestly whether it needs custom code — or just a rule.