Custom Shopify development

When your Shopify store needs more than a theme setting

Shopify covers most of what an online store needs. Then comes the request that no setting or app solves cleanly: a payment provider that isn’t offered in your checkout, a product page that has to work differently, orders that must reach another tool, or a theme that has grown slow and hard to edit.

Checkout Flow builds those missing pieces: custom Shopify features and integrations, designed for your store and tested before they reach your customers.

Who we work with

• Merchants already selling on Shopify who need a feature their theme or apps don’t provide.
• Businesses moving to Shopify that must keep a payment provider or a tool they already use.
• Teams who want their store connected to the rest of their systems instead of copying data by hand.

Hire a Shopify developer, without the guesswork

Hiring a Shopify developer usually means choosing between a marketplace freelancer you have to brief and supervise, and an agency that sells a full redesign. Checkout Flow sits in between: a developer who specialises in the hard parts of Shopify (payments, checkout, integrations, custom features) and works with a clear scope.

• A written scope and quote before any work: what will be built, what will not, and how it will be tested.
• Work on a copy of your theme or a test store, so your live store is never the test environment.
• Code you can maintain: sections and settings editable in the Shopify theme editor, documentation at hand-over.
• English or French, remotely.

What we build on Shopify

Payment and checkout integrations

Connecting a payment provider that isn’t available in your Shopify checkout, starting with our flagship SumUp Shopify integration. For PayPal, card payments or your current provider, see payment gateway integration.

Custom theme features

Sections, product pages, configurators, quote forms and buying journeys built into your theme, editable from the Shopify theme editor and available in your store’s languages.

Integrations with your tools

Orders, customers and stock exchanged between Shopify and the software you already use (accounting, ERP, CRM), through the Shopify Admin API and webhooks. See Shopify integrations and our API integration services.

Speed and maintainability

Reviewing a theme that has become slow or hard to change, removing what isn’t used and rebuilding what matters, without stopping your sales.

How a Shopify project runs

1. Review. You describe the need; we look at your store, your theme and your apps, then reply with a recommendation and a quote.
2. Build on a copy. We work on an unpublished copy of your theme or in a test environment, never directly on what your customers see.
3. Test. We test the agreed scenarios on desktop and mobile, in each language your store uses.
4. Go live. We publish when it suits you and hand over the documentation. Follow-up is defined in your quote.

Technologies

Shopify Online Store 2.0 themes (Liquid, JSON templates, sections and blocks), the Shopify Admin GraphQL API, webhooks and custom back-end services when an integration needs a server. We choose the simplest option that does the job and avoid adding apps you don’t need.

What we don’t claim

Checkout Flow is an independent service provider. We are not Shopify, nor an official Shopify partner, and we don’t present any integration as approved by Shopify or by a payment provider. Shopify and the payment providers you use remain your direct providers.

Frequently asked questions

Can you work on my current theme?

Yes. We can build on your current theme or on a recent official Shopify theme, depending on what’s best for your store.

Will my store stay online during the work?

Yes. The work is done on an unpublished copy or a test environment, and switched over when you’re ready.

How much does a Shopify project cost?

Every project is priced on quote, based on its scope. Describe your project and we’ll reply with a recommendation and a quote.

Do you work with businesses outside France?

Yes. We work remotely, in English or French.