Senior Shopify Integration Engineer (React / Customizer) – Contract

Working at Tech Holding isn't just a job, it's an opportunity to be a part of something bigger. We are a full-service consulting firm that was founded on the premise of delivering predictable outcomes and high-quality solutions to our clients.  Our founders and team members have industry experience and have held senior positions in a wide variety of companies – from emerging startups to large Fortune 50 firms – and we have taken our combined experiences and developed a unique approach that is supported by the principles of deep expertise, integrity, transparency, and dependability.

We are seeking a Senior Shopify Integration Engineer, for a project-based assignment, to lead the integration of a custom React-based product customization application into a Shopify Plus storefront.
This is a highly hands-on role focused on connecting an external product configurator with Shopify’s commerce engine. You will own the end-to-end integration, ensuring seamless data flow between systems, including pricing logic, customization data, order metadata, and downstream workflows such as internal notifications and email triggers.
You will be responsible for designing and implementing bidirectional communication between the React application and Shopify, enabling a premium, real-time customization experience for end users.

• →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

• 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