Theme architecture: settings, blocks and the limits of each

Online Store 2.0 gives you sections on every template, blocks within sections, and settings at both the section and theme level. The architecture question is which of those three a given requirement belongs in — and the answer is usually obvious once the layers are described properly.

A section is a job. "Show the customer social proof." "Explain the shipping promise." "Compare these products." It occupies a slot on a page and a merchandiser can add, remove or reorder it.

A block is a repeatable item inside that job. One testimonial within a social proof section. One row within a comparison. Blocks are the answer when the merchandiser needs three of something, or seven, and you do not know which in advance.

A setting is a choice. Heading text, an image, an alignment, whether to show prices. Settings live on a section or on a block, and occasionally — rarely — on the theme.

The most common theme problem we inherit is twelve sections that are four sections with variations. "Hero image left", "Hero image right", "Hero video", "Hero text only" are not four jobs. They are one job with a layout setting and a media setting.

It happens because each variant was requested separately, months apart, and adding a new section is the fastest way to satisfy a request without touching anything that already works. Every one of those decisions is locally reasonable and the aggregate is a theme with sixty sections where nobody knows which to use.

The test is simple: if you can describe two sections with the same sentence, they are one section. Merge them, expose the difference as a setting, and migrate the pages using the old ones rather than leaving them behind.

Blocks answer "how many", not "what sort". A features section with a block per feature is right — the merchandiser might want three or six. A features section with separate block types for "feature with icon", "feature with image" and "feature with number" is usually one block type with a media setting.

There is a real exception. When blocks genuinely behave differently — a rich text block beside an image block beside a video block, arranged freely — multiple block types are the correct model, and this is exactly what Shopify’s own flexible content sections do.

The distinction is whether the blocks are interchangeable items of the same kind, or genuinely different things sharing a container.

Section names outlive designs. "Three-column grid" describes a layout that will be redesigned within two years, at which point the name is actively misleading — it will be two columns and still called the other thing.

"Product comparison", "shipping reassurance", "editorial split" describe jobs. They survive a redesign, they are searchable by someone who did not build them, and they make the theme editor legible to a merchandiser who joined last month.

Theme-level settings apply everywhere and are therefore the hardest to change later. Brand colours, typography and the spacing scale belong there — they are genuinely global and they should be defined once.

Almost nothing else does. A theme setting for "default heading size on product pages" looks tidy and becomes the reason a change cannot be made to one template without affecting five. Prefer section settings, which are local and cheap, and accept the small duplication.

• Shopify theme customization
• Building a section library
• Figma to Shopify