Senior Full Stack Engineer

At EY, were all in to shape your future with confidence. Well help you succeed in a globally connected powerhouse of diverse teams and take your career wherever you want it to go. Join EY and help to build a better working world. The Opportunity We are looking for a great colleague to join our EY Tech People team as a Senior Fullstack Engineer, where you will play a pivotal role in building innovative tax automation tools and AI-integrated platforms across several business-critical products. Our mission is to enhance efficiency, quality, and satisfaction in tax and compliance workflows, serving thousands of clients with accurate and compliant tax filings. As part of a dynamic organization operating across the Nordics (DK, FI, SE, NO), you will collaborate with a talented group of engineers, designers, researchers and product managers in a flat, informal structure. While experience in tax law is beneficial, a passion for technology and collaboration is what we truly value. Your Key Responsibilities Building end-to-end tax automation features from React frontends to Node.js backends Developing AI-integrated platforms with seamless user experiences and robust data processing Close collaboration with designers, product managers, and fellow developers as well as sparring with users and researchers to understand tax workflows in detail Contributing to internal tooling and developer experience, including AI-assisted development workflows, MCP server implementations, and prompt libraries Working across a range of products and problem spaces in the fullstack domain Skills And Attributes For Success To thrive in this role, you possess a strong foundation in both frontend and backend technologies. To qualify for the role, you should have: Frontend Expertise (Required): React/TypeScript: Extensive experience with modern hooks, state management, and performance optimization Modern Tooling: Experience with build tools (Vite/webpack), testing frameworks (Cypress/Playwright), and Kubernetes deployments Complex UI Development: Building multi-step workflows, sophisticated form validation, and responsive interfaces Backend Proficiency (Required): Node.js: Extensive experience with Express, async programming, and RESTful API development MongoDB: Strong experience with document design, aggregation pipelines, and performance optimization Python Integration: Experience with FastAPI, report generation, and GenAI pipeline integration System Integration: Third-party API integration, microservices patterns, and MCP implementations What We Look For We are seeking a detail-oriented Fullstack Engineer with the ability to communicate technical concepts clearly with both technical and non-technical stakeholders. We imagine you as someone quick to solve complex problems and with the ability to question technical approaches and challenge architectural decisions. You are also eager to learn about advancements in fullstack technologies and tax domain complexities. A practical engineering mindset focused on delivering impactful solutions will help you succeed in this role. Furthermore, our new colleague is someone who embodies more than just technical expertise. We are looking for a supportive team member, ready to share knowledge and help others grow. You are based in either Copenhagen, Helsinki or Stockholm. What We Offer A tech product team: EYs Tech People organization as a unit operates mostly product- and user-driven, even though we are situated within a large consultancy organization Direct access to users: Your fullstack solutions will directly impact tax professionals who are quite literally right next to you, providing immediate feedback on both UX and system performance Full-stack ownership: Take features from concept to deployment with complete technical ownership Technology growth: Work with other great Engineers on React patterns, Node.js performance optimization, and AI integration challenges among other things. Good food and good times: We take good care of the people who dedicate their working hours to our cause Diverse and inclusive culture: You'll be embraced for who you are and empowered to use your voice to help others find theirs Please apply with your CV and Cover Letter no later than March 22nd, 2026. We review applications on an ongoing basis so please apply right away. For questions regarding the role, do not hesitate to contact [email protected] If questions regarding the recruitment process, please contact [email protected]. We look forward to your application! EY | Building a better working world EY is building a better working world by creating new value for clients, people, society and the planet, while building trust in capital markets. Enabled by data, AI and advanced technology, EY teams help clients shape the future with confidence and develop answers for the most pressing issues of today and tomorrow. EY teams work across a full spectrum of services in assurance, consulting, tax, strategy and transactions. Fueled by sector insights, a globally connected, multi-disciplinary network and diverse ecosystem partners, EY teams can provide services in more than 150 countries and territories.