Shopify app development & integrations

Shopify is powerful, but every growing brand eventually hits the limits of what themes and the app store alone can do. That is where custom development comes in — tailored apps, API integrations and backend systems that make your store work the way your business actually operates.

We build private Shopify apps, custom admin extensions, middleware for order routing and inventory sync, ERP integrations and automation workflows. Our work includes The List, our own B2B commerce app for trade accounts and credit management, plus bespoke integrations for automotive, trade and subscription businesses.

Every integration is scoped around reliability and maintainability. We document APIs, handle error states gracefully and test at volume before anything touches production.

Apps, extensions and middleware

Most of this work is private. A public App Store listing is a product business; a private app is how one merchant closes a gap the theme and the existing apps cannot. That might be an admin extension your team actually uses, a webhook flow that creates or updates orders, or a service that sits between Shopify and an ERP so the two systems stop being updated by spreadsheet.

The List, our own B2B app, is the in-house example: trade accounts, credit and order lists for merchants who cannot run wholesale through a consumer theme. Client work looks more like Torque GT’s ERP connection, Anchor Crafts’ order middleware, or Contamac’s automation. The pattern is the same even when the systems differ. Something in the business does not fit an off-the-shelf app, and pretending it does costs more over a year than building the narrow thing you need.

What we refuse to leave vague

Integrations fail in the exceptions. A product that exists in the ERP and not in Shopify, a partial fulfilment, a refund, a SKU that changed code, a timeout from the warehouse system at 6pm. The scope names those cases. We document the APIs, log failures somewhere a person can see them, and test with a volume that resembles a real day rather than three sample orders.

We will also tell you when an existing app is the better buy. Custom code you have to host and maintain is the wrong answer for a problem Shopify or a well-supported app already solves. Custom is for the workflow that is specific to how you take money, ship, or account for it.

How an integration project runs

Discovery writes down the systems, the direction of each piece of data, and who is the source of truth. Build happens against a development store and a sandbox of the other system wherever one exists. We do not point a new integration at production orders on day one. UAT is with the people who will notice a wrong stock figure, then we schedule the cutover and watch the first real orders.

Handover includes how to tell that the job is healthy next month, not only how it was deployed. If you want us to keep owning it, that is a retainer from £2,500 a month, shared with the rest of the store rather than a separate mystery contract.

Access is often what sets the timeline. An ERP sandbox, a Shopify app install, and someone who can confirm a stock figure matter more than extra development days. If there is no sandbox, we agree a development store and a short list of live SKUs rather than learning on the whole catalogue.