E-commerce · 2025

Shopify Checkout Extension & Custom Accounts

Production checkout extension for birthday collection with Klaviyo sync and a custom tiered rewards account page.

Custom Shopify development for CAPULET, a German D2C jewelry brand. Built a Checkout UI Extension using the latest Shopify Checkout Extensions API (2025-07) that collects customer birthdays on the Thank You page and syncs them to Klaviyo for automated birthday marketing campaigns. Also developed a custom customer accounts page with a tiered loyalty rewards system powered by the LoyaltyLion API, Shopify metafields, and Shopify Flow automations.

The Challenge

The brand needed a way to collect customer birthdays post-purchase without disrupting the checkout flow, then automatically trigger birthday campaigns through Klaviyo. They also wanted a custom loyalty experience beyond LoyaltyLion's default widget: a branded account page showing tier status, rewards progress, and personalized benefits.

Our Solution

Built a Shopify Checkout UI Extension targeting purchase.thank-you.block.render with 12 merchant-configurable settings, automatic email detection via the useEmail() hook, and real-time Klaviyo profile sync through a custom backend. Created a custom Liquid customer accounts page that integrates the LoyaltyLion API to display tiered rewards, connects to Shopify metafields for personalized data, and uses Shopify Flow for automated tier progression.