Shopify Plus Development
Senior Shopify Plus engineering for brands scaling past eight figures.
· Reviewed by senior engineers
01 What it is
What this service is
Shopify Plus development is the engineering work that takes a Shopify store from a configured theme to a properly engineered commerce platform. It covers theme architecture in Liquid or Hydrogen, custom app development, Shopify Functions (the replacement for Scripts), Checkout Extensibility, Flow automations, B2B configuration, multi-currency and multi-language storefronts, and the integrations that connect Shopify to your ERP, OMS, 3PL, CRM, and tax engine.
Shopify Plus is a far more capable platform than people who last looked at it five years ago realise. Checkout Extensibility means you can extend the one-page checkout with React-based UI extensions without forking, Shopify Functions let you write custom discount, shipping, and payment logic in Rust or JavaScript that runs at the platform level, and the Storefront and Admin APIs are now genuinely first-class. We treat Shopify Plus as a serious commerce engine, not a templated DIY tool.
What we do not do is sell you a theme and call it a day. We work the same way we would on any production application: typed code, Shopify CLI workflows, CI/CD with theme preview deploys per branch, Storybook for components, and observability across the apps and integrations we ship.
02 What it's for
What it's for
Shopify Plus is the right platform for a wide band of brands. A US DTC skincare brand turning over fifty million dollars that needs subscription, post-purchase upsells, and a serious site speed; a UK fashion label expanding to Germany, France, and the US with localised checkout, VAT and OSS handling, and Klarna alongside card; a B2B distributor in Australia who wants company-level pricing, net-thirty terms, and customer-specific catalogues without a custom build.
It is the right replatform target when you are escaping Magento 2 (where the maintenance burden has become unsustainable), Salesforce Commerce Cloud (where every change is a six-figure engagement), or a hand-rolled stack that has aged out. We have run dozens of Magento-to-Shopify and SFCC-to-Shopify migrations and we are direct about what you gain and what you have to redesign.
It is not the right call for every catalogue. If you sell highly configurable industrial products with thousands of variant axes, or you need a heavily customised pricing engine for global B2B, we will tell you when commercetools or a custom build is the better answer. Most brands, though, are leaving Shopify Plus capability on the table.
03 How to use it
How to engage devinsta
We start with a Plus audit — your current theme, app stack, third-party services, Flow automations, and the data flowing through them. The output is a prioritised list of issues (performance, technical debt, missed Plus features) and a roadmap that sequences quick wins ahead of larger projects.
Delivery runs in two-week sprints. Theme work happens in a Git-backed Shopify CLI workflow with branch previews; app and Function work follows a normal application engineering pattern. Your team gets a Linear or Shortcut board and weekly demos on a real preview store, and we develop against your staging Shopify environment with anonymised production data.
Most engagements settle into a retainer post-launch. The Plus platform evolves quickly — Checkout Extensibility, B2B updates, new Functions APIs — and brands that stay on top of the changes meaningfully outperform brands that ship once and forget.
04 How to deploy
How we deploy it
Theme code lives in your Git repository, with the Shopify CLI driving deploys. Each pull request gets a preview theme deployed to your Plus store, password-protected and accessible to the team for review. Main-branch merges deploy to staging; production deploys are tagged releases with a documented rollback path that is genuinely one command.
Apps and Functions are hosted on our infrastructure or yours. Public apps deploy to Vercel or Fly; private and custom apps usually deploy to Cloud Run or Fargate inside your cloud account, with the Shopify webhook stream consumed through SQS or a similar queue so a Shopify outage does not drop events. We sign webhooks, validate them on receipt, store them idempotently, and replay from the queue when a downstream system is recovering.
We monitor everything. Shopify webhook deliveries, app uptime, Function execution counts, checkout conversion by region and payment method, and Core Web Vitals on the storefront — all surfaced in a single dashboard your team gets read access to. We set alerts on checkout conversion drops at the country level so a broken Klarna integration in Germany pages someone within minutes, not after the next finance review. For GDPR compliance we configure customer data requests through the GDPR webhooks, and we maintain a documented data-residency posture.
05 What we provide
What you get from us
- Shopify Plus audit covering theme, apps, Functions, Flow, and integrations
- Custom theme built on Dawn, a typed Liquid component library, or Hydrogen
- Shopify Functions for discount, shipping, payment, and delivery customisation
- Checkout UI extensions for upsell, cross-sell, and post-purchase flows
- Custom and embedded apps for the bespoke logic your business needs
- ERP, OMS, 3PL, tax (Avalara, TaxJar), and CRM integrations
- Multi-currency, multi-language, and multi-market storefront configuration
- Performance optimisation targeting sub-2-second LCP and Lighthouse 90+ on mobile
FAQ
Common questions
Should we use a stock Shopify theme or build custom?
Start with Dawn or a reputable paid theme if you are a smaller brand. Above five million in revenue, a custom theme almost always pays back through conversion lift and faster iteration. Above twenty million, headless Hydrogen becomes a serious option. We help you sequence the right move for your stage.
How do you handle migration from Magento or SFCC?
We run migrations as a phased project: data mapping first (customers, orders, products, redirects), then a parallel Shopify build, then a controlled cutover with DNS shift and a 301 redirect map. We have done dozens of these and SEO equity is preserved when the redirect strategy is done properly — which is most of the work.
Can Shopify Plus handle B2B with company hierarchies and net terms?
Yes. Shopify's B2B features have matured significantly. You get company profiles, location-based pricing, payment terms (including net thirty, net sixty), customer-specific catalogues, and quote requests out of the box. We extend these with custom apps where your workflow needs more than the platform provides.
What about performance? Shopify themes have a reputation for being slow.
That reputation comes from theme bloat — too many apps, unminified scripts, lazy images done badly. A properly built theme on Dawn or a custom architecture, with apps audited for performance impact, regularly scores 90+ on Lighthouse mobile and sub-2-second LCP. We benchmark performance as part of the audit and as a deliverable.