eCommerce Platform & Integration Engineer

As our eCommerce Platform & Integration Engineer, you’ll play a pivotal role in supporting the development, optimisation and scaling of our eCommerce platforms across Hallmark.co.uk and our marketplace channels. Working closely with Ecommerce, Marketing and Commercial teams, you’ll combine technical expertise with commercial awareness to deliver scalable, high‑performing solutions that enhance customer experience and support business growth.

You’ll focus on developing our Shopify ecosystem, building integrations across systems and supporting expansion into new sales channels, including marketplaces and dropship partnerships. Through continuous improvement and collaboration, you’ll help strengthen our core eCommerce capabilities and drive performance across all digital touchpoints.

Your Responsibilities

• Develop, maintain and enhance the Shopify storefront, including custom themes, applications and functionality.
• Customise Shopify themes using Liquid, JavaScript, HTML5 and CSS3 to deliver responsive and high‑performing user experiences. 
• Work with Shopify APIs to deliver advanced functionality and integrations.
• Build and maintain integrations across eCommerce platforms, marketplaces, OMS/WMS and third‑party partners.
• Support the onboarding of new sales channels including marketplaces and dropship partners.
• Work with systems and middleware tools to enable order management, fulfilment and data flows.
• Ensure accurate and scalable data flows across products, orders, pricing and inventory.
• Troubleshoot and resolve technical issues across platforms and integrations.
• Use analytics and performance data to identify and implement website and customer journey improvements.
• Support A/B testing and experimentation initiatives across the website.
• Implement UX and customer journey enhancements in collaboration with Ecommerce and Marketing teams.
• Support technical SEO improvements, including performance and site structure optimisation.
• Translate trading and optimisation opportunities into effective technical solutions.

Your Accountabilities

• Supporting the stability, scalability and performance of eCommerce platforms and integrations.
• Enabling expansion into new channels, including marketplaces and dropship partnerships.
• Delivering continuous improvements to website performance, customer experience and operational efficiency.
• Building in‑house capability and reducing reliance on external development agencies.
• Contributing to the development of the eCommerce technology roadmap and ecosystem.
• Ensuring all solutions are delivered in line with best practice, scalability and long‑term maintainability.

Key Relationships

• eCommerce Team
• Marketing Team
• International Tech/Development Team (US)
• Commercial & Operations Teams
• External technology partners and service providers

To Be Successful You Will Need

• Strong experience in Shopify development, including themes, apps, APIs and integrations.
• Advanced knowledge of JavaScript, HTML5 and CSS3.
• Experience working with Shopify APIs and integration architectures.
• Understanding of Shopify data structures, including objects and metafields.
• Experience working within an eCommerce environment.
• Strong problem‑solving skills with the ability to diagnose and resolve technical issues.
• Experience or exposure to multi‑channel commerce, including marketplaces or dropship models.
• Understanding of OMS/WMS platforms (desirable).
• Experience with analytics, tagging or performance tools (desirable).
• Experience working within structured development processes and tools (desirable).
• Ability to collaborate with cross‑functional teams and interpret design requirements.
• Exposure to A/B testing, CRO or UX optimisation (desirable).
• Commercial awareness and understanding of how technical decisions impact performance.
• Strong communication skills and a proactive, solutions‑focused mindset.