Changing the Theme Without Making It Unmaintainable

Theme updates are the trade-off

Shopify themes receive updates — performance improvements, new features, compatibility fixes. A heavily-modified theme cannot take those updates without redoing the modifications.

That is an acceptable trade for genuine requirements and a poor one for cosmetic tinkering. Knowing which is which is the discipline.

Contain the changes

• Custom styles in one file, not scattered through templates
• Custom snippets clearly named and documented
• A written record of every modification and why it was made
• Nothing modified that the theme settings could have achieved

The record matters more than people expect. Three years later, nobody remembers why a template was changed, and that uncertainty makes every future change slower.

Use theme settings first

Modern Shopify themes expose a great deal through settings and sections. A substantial share of the customisation requests we receive are achievable without touching code.

Check the settings thoroughly before commissioning a change. It is free, it survives updates, and your team can adjust it themselves.

Keep business logic out

Pricing rules, integrations and anything that must survive a theme change belong in an app or in Shopify Functions, not in Liquid templates.

A store that changes theme and loses its bundle pricing has paid for that logic twice, which is entirely avoidable.

Test on a duplicate

1. Duplicate the theme before making changes
2. Make and test the changes on the duplicate
3. Check product, collection, cart and mobile specifically
4. Publish when it is right, keeping the previous version
5. Verify the live store after publishing

Frequently asked questions