Shopify & eCommerce
Shopify Functions
Quick definition
Server-side WebAssembly modules that run custom logic at checkout — discounts, shipping rules, payment customizations, validation.
What it actually means
Shopify Functions execute in Shopify's infrastructure at sub-50ms per checkout event. They replace the discount apps, custom shipping calculators, and payment customizer apps that previously bloated Plus stores. A well-built Functions setup can collapse 5-10 paid apps into native logic, improving both checkout speed and reducing monthly app spend by $500-$2,000.
Related terms
Shopify Plus
Shopify's enterprise tier for brands above ~$1M ARR. Adds checkout extensibility, B2B, multi-store, dedicated launch manager, higher API limits.
Checkout Extensibility (Shopify)
Shopify Plus's modern checkout customization model using web pixels, UI extensions, and Functions — replacing the deprecated checkout.liquid.