Senior Shopify Integration Engineer (React / Customizer) – Contract

Tech Holding is a full-service consulting firm focused on delivering high-quality solutions to clients. They are seeking a Senior Shopify Integration Engineer to lead the integration of a custom React-based product customization application into a Shopify Plus storefront, ensuring seamless data flow and a premium user experience.

Responsibilities:

• Lead the integration of a standalone React-based product customizer into a Shopify Plus storefront (via iframe or app integration)
• Design and implement secure cross-application data exchange between the custom app and Shopify (e.g., postMessage, iframe communication, APIs)
• Build dynamic pricing logic based on user customization inputs (materials, placements, add-ons, etc.)
• Capture and persist customization data through the Shopify cart and checkout using line-item properties
• Implement 'Add to Cart' flows that include custom metadata and generated product previews
• Configure backend workflows using Shopify Webhooks to trigger internal processes, notifications, and email-based workflows (e.g., order events, production handoff)
• Ensure high performance and responsiveness across desktop and mobile environments
• Collaborate with frontend, backend, and product teams to ensure a seamless user experience

Requirements:

• 5+ years of experience with Shopify development, including Shopify Plus
• Strong experience integrating custom applications into Shopify storefronts (not just theme development)
• Proficiency in React.js and modern frontend development
• Experience with Shopify Storefront API, Admin API, and custom apps
• Hands-on experience implementing cross-application communication (e.g., postMessage, iframe integrations, APIs)
• Experience working with Shopify cart and checkout flows, including line-item properties
• Strong understanding of JavaScript, web security, and cross-origin communication
• Experience troubleshooting complex frontend/backend integration issues
• Experience building or integrating product customization tools (2D/3D configurators)
• Familiarity with dynamic image generation (canvas, layering, previews)
• Experience with Shopify Webhooks and event-driven workflows
• Experience in e-commerce, retail, or made-to-order product environments
• Experience with Klaviyo or transactional email workflows