Senior Fullstack Engineer (Next.js/Node.js/AWS)

About the role:

You will own the frontend of a high-traffic headless storefront and the Node.js services behind it, serving customers across Europe, Latin America and APAC. Page speed here is not a nice-to-have, it maps directly to conversion, so your work centres on rendering strategy, caching and delivery at the edge. You will work day to day with the client's engineering team in Europe, contributing to architecture decisions rather than just implementing tickets.

In this role, you will:

• Lead the design and development of a multi-market storefront in Next.js and TypeScript, covering catalog, product pages, cart and checkout flows.

• Choose and justify the right rendering strategy per surface (static, incremental, server-rendered, client-side) based on traffic patterns and freshness needs.

• Design the caching layer end to end, from CDN and edge through to browser, including invalidation when product, price or inventory data changes.

• Own the performance budget and optimise across regions, from bundle size and hydration cost through to time to first byte.

• Build and maintain the orchestration layer between the storefront and commerce services using Node.js with REST or GraphQL.

• Handle multi-currency and multilingual storefront experiences so each market gets the right catalog, language and pricing.

• Implement and iterate on payment and checkout flows, working with gateways such as Stripe, PayPal, Klarna, Apple Pay and Google Pay.

• Support A/B testing and analytics tracking so product decisions are backed by data.

• Guarantee test coverage with unit, integration and end-to-end testing, and keep CI/CD pipelines healthy.

• Support observability and operational excellence with proper logging, monitoring and rollback procedures, leveraging AWS where applicable.

• Guide and mentor mid-level engineers, and share context with both the Gradion team and the client's engineers.

• Experiment with AI developer tools (Cursor, Claude, Copilot).

The engineer we're looking for:

• Driver, Not Passive Coder: You challenge requirements, propose alternatives and take decisions to a conclusion instead of waiting to be told.

• Depth Over Breadth: You can explain what actually happens between a user typing a URL and the page becoming interactive, not just name the tools involved.

• Honest About Gaps: You say clearly when you do not know something, then go find out.

• Proactive Communicator: In a distributed team across several time zones, you ask the clarifying question early rather than guessing.

What you will bring:

• 5+ years of engineering experience on production web applications at scale, with your recent work weighted towards the frontend.

• Strong command of TypeScript, React and Next.js, plus deep JavaScript and browser fundamentals.

• Backend experience with Node.js and REST or GraphQL APIs, including designing the orchestration layer between storefront and commerce services.

• Solid understanding of rendering and caching strategies, and the ability to reason about the trade-offs between them.

• Hands-on experience deploying to a CDN or edge platform such as Cloudflare, Vercel or CloudFront.

• Working exposure to AWS (Lambda, S3 or similar services), enough to reason about how your application is deployed and run.

• Experience with automated testing and CI/CD pipelines.

• Good spoken and written English. You will be in daily technical discussion with European engineers, including live architecture and pairing sessions.

• Willingness to learn the Shopify ecosystem, even if you have not used it before.

Nice-to-Have:

• Experience with Shopify, especially headless setups using the Storefront API, Functions or Checkout UI Extensions.

• Background in e-commerce or another conversion-driven product.

• Experience with subscription or recurring purchase flows.

• Hands-on with Playwright or Cypress, and with analytics tools.

• Familiarity with headless CMS platforms.