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ecommerce

Custom Shopify Platform Build for mdlondon

How we built Horizon — a production-grade custom Shopify theme with full test coverage, CI/CD pipeline, and a five-pillar strategic framework — for one of the UK's fastest-growing premium hair tools brands.

76
Automated tests

Unit and visual tests protecting theme integrity across every component

36
Visual snapshots

Regression testing ensuring no update silently alters the brand's visual identity

WCAG 2.1 AA
Accessibility

Full accessibility compliance built into the theme from the ground up

3 environments
Deployment pipeline

Dev → staging → production CI/CD pipeline via GitHub Actions

The Challenge

mdlondon, a premium D2C hair styling tools brand, had outgrown the constraints of off-the-shelf Shopify themes. Routine changes required developer involvement. Performance was inconsistent. There was no test coverage, no deployment pipeline, and no confidence that updates wouldn't break production. The brand had serious growth ambitions and needed a platform built to match them.

The Solution

We built Horizon — a custom Shopify theme from scratch, designed to be owned and maintained by mdlondon's team without ongoing agency dependency. Full design token system, WCAG 2.1 AA accessibility compliance, three-environment CI/CD pipeline, and 76 automated tests ensuring any change that breaks the theme is caught before it reaches customers. Alongside the technical build, we developed a five-pillar growth framework covering technology, marketing, operations, brand development, and product expansion.

The Site

mdlondon homepage — The Numbers campaign hero
Homepage Visit
mdlondon product collection — All styling tools
Collection page Visit
BLOW Hair Dryer product page — 650 verified reviews
Product page Visit

The Challenge: A Brand Ready to Scale, Constrained by Its Platform

Most growing D2C brands hit the same wall. The Shopify store was built to launch the product, not to scale the business. The result is a theme that requires agency involvement for routine changes, performance that degrades as the product catalogue grows, and a codebase that nobody fully understands.

mdlondon had a quality product and real growth ambition. Their team was capable. What they needed was a platform built to the same standard as the brand — one they could own, iterate on, and grow without being perpetually dependent on external developers.

The specific problems:

  • No test coverage: Any update could silently break something. Deploying changes was a manual, anxiety-inducing process
  • No deployment pipeline: Changes went straight from development to production with no staging environment or automated checks
  • Performance inconsistency: Core Web Vitals weren’t reliably passing, affecting organic search and conversion
  • Accessibility gaps: The theme wasn’t built to a consistent accessibility standard, creating legal exposure and a worse experience for a portion of customers
  • Design rigidity: Brand changes required touching dozens of individual components rather than a centralised system

The Solution: A Theme Built Like a Product

We built Horizon from scratch — treating it as a software product rather than a theme customisation.

Design Token System

The foundation of Horizon is a comprehensive design token system. Every colour, typographic scale, spacing value, and component state is defined as a token. When mdlondon’s brand evolves, changes propagate consistently across the entire store. No hunting through individual templates. No inconsistencies between components.

Test Infrastructure

We wrote 76 automated tests and 36 visual regression snapshots — covering every theme component and key user flows. The tests run automatically on every pull request. Anything that breaks the theme or silently alters the visual design is caught before it reaches production.

For a brand where the customer experience is directly tied to purchase confidence, this matters. You don’t ship fixes that introduce new problems.

Three-Environment CI/CD Pipeline

We built a proper deployment pipeline: development → staging → production, automated via GitHub Actions. Every change is tested, reviewed, and deployed through a controlled process. The staging environment mirrors production exactly, so what you test is what you ship.

WCAG 2.1 AA Accessibility

Accessibility was built in from the start, not retrofitted. The full theme meets WCAG 2.1 AA standards — semantic HTML, keyboard navigation, screen reader support, colour contrast compliance. Beyond the compliance argument, it’s a better experience for every customer.

Core Web Vitals

Page speed and performance are baked into the theme architecture. Horizon passes Core Web Vitals across all key pages — important both for search visibility and for the conversion rates that matter on a D2C brand.

The Strategic Framework

Technical delivery was one part of the engagement. We also developed a five-pillar growth framework with mdlondon’s team: covering technology, marketing and customer acquisition, operations, brand development, and product expansion. The framework gave the business a structured approach to scaling — not just a new platform, but a roadmap for what to do with it.

The Result

mdlondon now has a Shopify platform built to production software standards. Their team can ship updates confidently, knowing the test suite will catch problems before customers do. The design token system means the brand can evolve without rebuilding. And the strategic framework gives them a clear path to the next phase of growth.

This is what it looks like when a Shopify store is built to last — not just built to launch.

If your brand has outgrown its platform, let’s talk.

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