Shopify Plus Development Agency UK

Senior engineers building Shopify Plus stores, custom apps, headless storefronts, and B2B integrations for UK and EU brands. Built from your requirements, not a theme. Engineering done properly.

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  • Shopify Plus Partner
  • Senior engineers only
  • London based
Recent build: Veluare, luxury jewellery launch on Shopify

Our Shopify development process

  1. Discovery. Engineer-led brief. We pull your stack, integrations, and growth goals into a written scoping document before any code is touched.
  2. Build. Theme, custom app, Functions, Hydrogen, or B2B catalogue work, picked to the brief, not pushed because the agency only has one tool.
  3. QA + UAT. Side-by-side regression on a sample of representative orders, integration replays, performance budget verification before any DNS swap.
  4. Launch + support. Cutover during low-traffic hours, monitoring window, and a scoped post-launch support period agreed in writing before the engagement closes.

What's included

  • A senior engineer on every project: no junior-only teams, no offshore sub-contracting
  • Shopify Plus, BigCommerce, SFCC, and NetSuite expertise in one team, useful when integrations cross platforms
  • Written architecture briefs, risk registers, and rollback plans you own and can re-read
  • Direct engineering communication: Slack or email with the people writing the code, not an account manager intermediary
  • Post-launch retainer option for ongoing performance, security, and feature work

Project timeline

Scoped per project

Project shape decides duration. A custom app in two weeks; a Plus migration in 8-12 weeks; a headless rebuild in 12-20 weeks. We confirm a window in writing once the discovery scan surfaces the real shape of the work. Quoting a fixed day-count beforehand is how scope creep starts.

Pricing and timelines

Verified September 2026. GBP, ex VAT.

EngagementTypical feeDurationWhat is in scope
Custom Shopify app (private, single purpose)£4,000 to £25,0002 to 6 weeks
  • One Admin API or Storefront API integration, or one automated workflow
  • Written brief, test suite, deployment on your Shopify Partner account
  • Two weeks of post-launch fixes included
Shopify Plus build (theme, Functions, B2B)£30,000 to £120,0008 to 16 weeks
  • Online Store 2.0 theme built from your requirements, not a purchased template
  • Checkout Extensibility, Shopify Functions, B2B catalogues and Markets as the brief needs
  • ERP, CRM or 3PL integrations, side-by-side regression before cutover
Headless Hydrogen storefront£30,000 to £200,00012 to 20 weeks
  • Hydrogen 2.0 on Oxygen, Storefront API, custom checkout experience
  • Performance budget agreed up front and verified before launch
  • Rollback plan and architecture brief you own
Rescue or hand-over auditScoped separately1 week
  • Read of the existing codebase and integrations
  • Realistic cost to reach launch, and whether a partial rebuild is the honest route
  • Separately scoped; credited against the build if we continue

Firm pricing goes in writing after the discovery scan. The bands above are where the last twelve months of engagements landed; a project outside them is unusual, not impossible.

FAQ

What does a typical engagement cost?

Custom apps span £4K (single-purpose private) to £250K+ (App Store SaaS). Theme + Plus build engagements typically £30K-£120K depending on B2B and integration scope. Headless Hydrogen builds typically £30K-£200K. We share firm pricing in writing once the discovery scan is complete. Quoting before we've seen the brief is unfair to both sides.

How is No7 different from a freelance Shopify developer?

Freelancers are great for a single, well-defined task. We're built for engagements where multiple disciplines collide: custom apps that talk to ERP, headless storefronts that need to keep Plus features, B2B catalogues bridging Shopify and SFCC. We bring the senior engineer + architect + integration specialist as one team rather than asking the merchant to coordinate three separate freelancers.

Are you a Shopify Plus Partner?

Yes. Shopify Plus Partner certification means we have direct access to Plus support, early-feature beta channels, and the partner-tier pricing structure for new merchants. The certification is a baseline though. What we hire for is engineering depth across Plus internals (Functions, Flow, Markets, B2B), which the certification does not test.

Do you do theme work or only custom apps?

Both. We work across the full surface: Online Store 2.0 themes, Liquid customisation, custom apps (private and App Store), Checkout Extensibility, Functions, Hydrogen storefronts, and Flow automation. Most engagements mix two or three of these; we pick what the brief actually needs.

Can you take over a project that another agency started?

Yes. About a third of our work is rescue or hand-over. We start with a one-week stack audit (separately scoped) so we can give you an honest read on the existing codebase, the realistic cost to bring it to launch, and whether a partial rebuild is more honest than continuing.

Where are you based and which time zones do you cover?

London-based (Covent Garden). Remote-first across UK + EU + US Eastern overlap. Most of our merchants are UK + EU, with a meaningful slice on US Eastern. We schedule across these zones; deeper APAC coverage is engagement-specific.

Related services & guides

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