Shopify Functions Development

Shopify Functions are where the real logic lives. When the native settings cannot express your promotion, your shipping rules or your payment logic, a Function can, and because it runs on Shopify’s own infrastructure, it stays fast and reliable under load.

The logic behind the storefront

Functions are code, and writing them well takes engineering judgement: handling edge cases, keeping them performant within Shopify’s limits, and making them configurable so your team controls the rules without a redeploy. We have built this exact class of logic across our own Shopify apps, so we know where the sharp edges are.

What we build most

Discount Functions for tiered, volume and conditional promotions. Payment and delivery customization to hide, rename and reorder methods per order. Cart and checkout validation to enforce minimums, limits and restrictions. Bundling and pricing logic that native features cannot reach.

Every type of Shopify Function we build

Shopify has a separate Function API for each part of checkout and fulfillment logic, and each one has its own page:

• Discount Functions: tiered and volume pricing, BOGO, gifts with purchase and shipping discounts.
• Cart Transform: product bundles, kits and paid add-ons.
• Payment customization: hide, rename and reorder payment methods, plus B2B payment terms.
• Delivery customization: hide, rename and reorder shipping, local delivery and pickup options.
• Cart and checkout validation: order minimums, purchase limits and restricted products.
• Fulfillment constraints: which locations may ship which items.
• Order routing: which location ships each order, on Shopify Plus by request.

Shopify’s local pickup and pickup point Functions are still in developer preview, so we do not build production work on them yet.

After Shopify Scripts

Shopify switched Scripts off on June 30, 2026. If a promotion, shipping rule or payment rule quietly disappeared with them, it can come back as a Function. We reconstruct what each Script did, rebuild it, and test it against real carts so customers see the right prices and options again. Our Scripts to Functions migration service covers the full process.