Fullstack Software Engineer (React/Next.js, XML, Domibus AS4) (m/f/n)

We are currently looking for an experienced Fullstack Software Engineer to join a long-term project for a European Union institution. You will be involved in the development, integration, and maintenance of modern full-stack applications within an international environment, supporting digital public services and cross-border cooperation initiatives across Europe.

• University degree at Master's level (MSc, MA, MEng or equivalent).
• Minimum 5 years of professional software development experience.
• Frontend: minimum 4 years with TanStack React Query, minimum 6 years with React and Next.js, minimum 6 years with Tailwind CSS.
• Backend: minimum 6 years with Fastify, minimum 6 years with Axios, Pino, and Vitest.
• Minimum 2 years experience integrating with AS4 messaging solutions (e.g., Domibus AS4 Backend API).
• Minimum 3 years with GitLab for source code management and CI/CD.
• Minimum 5 years with pnpm, Nx, and Biome.
• Minimum 2 years experience with XML, XSLT, xml-js, xml-crypto, xmllint-wasm, and Saxon-JS.
• Minimum 1 year experience working with information systems implementing the Once-Only Principle, preferably within public administration or public-sector environments.
• English language at minimum B2 level (CEFR).

Nice to have:

• Experience working in Agile development environments.
• Familiarity with Agile ceremonies including sprint planning, reviews, retrospectives, and daily stand-ups.
• EU citizenship is mandatory.
• Candidates must perform their work from the territory of a European Union Member State.

• Develop and maintain frontend and backend application components.
• Build modern web interfaces and integrate them with backend services and APIs.
• Write clean, maintainable, and well-tested code.
• Perform troubleshooting, debugging, and resolution of technical issues.
• Conduct unit and integration testing.
• Create and maintain technical documentation.
• Deliver solutions that meet both functional and non-functional requirements.
• Support application deployments and releases using CI/CD practices.
• Participate in the maintenance and continuous improvement of existing solutions.
• Collaborate with stakeholders, technical leads, and development teams in an Agile environment.

• EU citizenship is mandatory.
• Candidates must perform their work from the territory of a European Union Member State.