CASE STUDY · Shopify Plus · 2026
Calico Corners
Two production Shopify Plus features for a US home furnishings retailer, trade-tier pricing and checkout email validation.
2
- Calico Corners
- Home furnishings / Retail (US)
- Shopify Plus
- React Router v7, TypeScript, Shopify Functions, Polaris, Prisma, PostgreSQL, Liquid
- 2026
- Shopify & e-commerce
The brief
Calico Corners is a long-established US home furnishings retailer on Shopify Plus. Two production problems needed solving: trade-tier customers (Silver Designers) needed to see and pay trade pricing, which Shopify's stock pricing model doesn't support cleanly at the cart level; and checkout was accepting guest orders from emails that already had customer accounts, fragmenting customer history.
What we did
- Built a Checkout UI Extension that validates the contact email against existing customer accounts and prompts sign-in before checkout.
- Built a Shopify Cart Transform Function that rewrites cart pricing for Silver Designer customers at the checkout layer.
- Added theme-side snippets so trade pricing is consistent from PDP and collection pages through to checkout.
- Shipped both features to production behind the store's existing Plus setup.
How we built it
The app runs on Shopify's current recommended Plus scaffold, React Router v7 with TypeScript, Polaris admin UI, and Prisma + PostgreSQL for session storage. Cart Transform Functions are the right tool for tier pricing because they execute server-side at the checkout layer and stay auditable in Shopify's checkout logs; theme-side discounts get bypassed by direct checkout links, Cart Transform does not. The checkout extension uses Preact (Shopify's runtime) and proxies through a trusted backend with stored offline session credentials, because extensions cannot call Admin GraphQL directly.
The Cart Transform Function reads the customer's silverDesigner metafield
and the variant's tradePrice metafield, then rewrites matching line
prices. Because the rewrite happens at the checkout layer rather than in
the theme, it holds even when a customer reaches checkout through a direct
cart permalink.
The result
Both features are live in production. Silver Designer customers see correct trade pricing end to end, and customer history stays unified, no more orphaned guest orders for emails that already have accounts.
Live
“Such a pleasure working with DevonicWeb. They are reliable and consistently delivered functional, well-tested code. They were available throughout the process and answered all the questions. They communicated proactively and went beyond. Tip of the hat, DevonicWeb.”
Tech stack
- React Router v7
- TypeScript
- Shopify Functions
- Polaris
- Prisma
- PostgreSQL
- Liquid
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