Senior Fullstack Developer (ReactJS, NodeJS)

Job description

**ABOUT US:** At Gradion, we are the strategic partner for ambitious businesses, helping them achieve breakthrough growth through Digital Innovation and Deep Tech. With a global vision and an AI-first approach, we enable clients to reshape strategies, optimize systems, and adopt cutting-edge technologies to create sustainable value. From AI and data to cybersecurity, robotics, and large-scale enterprise platforms, Gradion designs practical solutions that lay the foundation for the next generation of billion-dollar companies. **OUR FACTS & FIGURES:** - 23+ years of expertise - Gradion builds digital platforms & deep-tech solutions. - 3 continents: Asia, Europe and Africa. - 300+ specialists across 7 countries Vietnam, Singapore, Thailand, Saudi Arabia, Germany, Egypt and Australia. - 100+ enterprise clients, including several unicorns (e.g., Alaiko, HomeToGo, Roadsurfer). - Vietnam’s Best IT Company - recognized by ITViec for 8 consecutive years, including 2 consecutive years of ranking #1 (2024 and 2025). - ISO 27001. ### 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). ### What you will bring - 5+ years of engineering experience on production web applications at scale. - 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.