I built a custom full stack Shopify app for 1MR (One More Rep), a fitness brand that needed a full-featured gym finder embedded directly inside their Shopify storefront. Users search for nearby gyms on a map, filter by amenities, and see live drive-time estimates from their current location.

Given the complex UI and back end requirements, I chose an app proxy with Next.js and React over a more traditional Liquid plus vanilla JS or Alpine setup. Next.js through the app proxy kept the whole stack consolidated and allowed for complex custom business logic and UI without the need for going full headless.

To stay within the client's AWS stack, drive-time matrix calculations were handled by AWS Location Service and used to enrich each gym record from the MongoDB geo-query.

Style scoping

Since app proxy HTML is injected directly into the merchant's theme, keeping styles isolated in both directions involved two pieces: a Tailwind tw- prefix, plus a custom PostCSS plugin that scoped every selector under #__proxy-theme. If I were building this project today, I'd reach for declarative shadow DOM for this purpose, which became baseline after this project shipped.