How does Shopify work?

Shopify is one of the most widely used ecommerce platforms in the world, chosen by small brands and large enterprises alike to sell online, in physical retail, and through channels such as Instagram, Amazon and TikTok.

At first glance it looks like a plug-and-play solution. Behind that simplicity sits a robust and surprisingly flexible infrastructure. This guide covers the key components, how the platform works technically, and what makes it scale.

SaaS architecture

Shopify runs as software as a service, which means you install nothing on your own servers. You pay a subscription to use the platform in the cloud, and Shopify manages the entire infrastructure. That gives you:

  • Automatic security and feature updates.
  • Scalability without the merchant thinking about server capacity.
  • Global delivery through a distributed CDN.

Shopify uses Kubernetes for container orchestration and runs primarily on Google Cloud Platform, with some workloads historically on Amazon Web Services. That is what lets it keep thousands of stores highly available at once.

Liquid, the templating engine

The most important technical building block is Liquid, the templating language created by Tobias Lütke, Shopify’s founder. Liquid is a safe, logic-limited language designed to generate dynamic HTML efficiently without exposing backend logic.

Its defining characteristics:

  • Tags, filters and objects as the core primitives.
  • Fully customisable themes.
  • A hard separation between business logic and presentation.

Liquid is not exclusive to Shopify. Jekyll and GitHub Pages use it too.

Theme structure

A Shopify theme typically contains:

  • Layouts: base templates such as theme.liquid.
  • Templates: per page type, such as product and collection templates.
  • Sections: reusable, configurable blocks.
  • Snippets: small fragments for contained functionality.
  • Assets: static CSS, JavaScript and images.
  • Config: theme settings in JSON, such as settings_schema.json.

Combining sections and blocks is what lets merchants build customisable pages from the visual editor without touching code.

Shopify APIs

Shopify exposes several APIs. The most important thing to know is that the REST Admin API is legacy. It was formally marked as such on 1 October 2024, critical endpoints including products and variants began shutting down from 1 February 2025, and all new apps are expected to use the GraphQL Admin API exclusively.

If you are commissioning a custom integration today and a developer proposes building it on the REST Admin API, that is a warning sign worth raising.

Beyond the Admin API, Shopify provides:

  • Storefront API: built for headless setups and custom frontends.
  • Ajax API: cart operations without a page reload, used heavily by traditional themes.
  • Webhooks: event notifications, for example when an order is created.

Apps

Shopify functionality extends through apps, which come in two forms. Public apps are distributed through the Shopify App Store. Custom apps are built for one specific store. Both talk to the store through the APIs above and generally authenticate with OAuth 2.0.

Headless commerce

Liquid still underpins most stores, but Shopify has invested heavily in headless commerce through two products. Hydrogen is a React-based framework optimised for Shopify. Oxygen is global hosting with server-side rendering for headless storefronts.

Together they let you separate frontend from backend completely, which suits projects that need maximum customisation or performance. It also raises your development cost meaningfully, so it is worth being honest about whether you need it.

Checkout

Checkout is one of the few elements you cannot freely modify on standard plans. Deep checkout customisation is a Shopify Plus capability.

That constraint keeps the buying process secure and consistent across the platform, which is genuinely valuable. It is also a real limitation if you need a fully bespoke checkout and are not on Plus.

What makes it work

Shopify shortens time to market, runs on reliable global infrastructure, and serves both non-technical merchants through its visual editor and developers through Liquid, its APIs, apps and headless stack. Security and PCI compliance are handled for you rather than being your problem.

If you are weighing it against what you run today, we compared it directly with Magento and Adobe Commerce and with PrestaShop. If you have already decided, here is how we run a Shopify migration.