Design and build modern React / Next.js applications that stay maintainable as they grow. Make and defend architectural decisions — and understand the performance consequences of them. Set front-end standards, build reusable components, and create patterns the whole team builds on. Work closely with our back-end developers to integrate APIs and business logic cleanly. Own quality end to end, including in production: reading logs, tracing issues, and diagnosing incidents together with our DevOps and sysadmins rather than handing them off. Improve performance, accessibility, and overall UX across projects. Review code, raise the bar, and help good front-enders across our teams become even better — without slowing them down. 5+ years in front-end development, with deep, current React and TypeScript experience. Real production experience with Next.js — you understand rendering strategies (SSR / SSG / ISR / CSR), hydration, routing, and when to use which , not just how to scaffold an app. A strong grasp of front-end architecture: component design, state management, and how structural choices affect maintainability, bundle size, and runtime performance. The ability to measure and improve performance (Core Web Vitals, bundle analysis, profiling) — and to understand the cost of the trade-offs you make. Solid experience integrating front-ends with APIs and back-end systems. Comfort across the full lifecycle: version control, testing, debugging, CI/CD, deployment, and maintenance. Excellent English and the confidence to work directly with product owners and clients. Senior judgment: you know when to be rigorous and when to be pragmatic, you take ownership of outcomes, and you make the people around you better. Nice to have: Python/Django and SQL (you'll work closely with our back-end teams), real depth in accessibility, a good design sensibility, or experience setting standards within a team. Challenging custom software projects. A highly skilled and technical team. Short communication lines and little bureaucracy. Significant influence on front-end architecture and development standards. Opportunities to improve processes and shape the future of front-end development within the company. A culture that values expertise, ownership, and continuous improvement. A salary between €3000 - €5000,- based on experience. A training budget for courses, certifications, and industry events. 25 vacation days to ensure sufficient rest and relaxation. An attractive (optional) pension plan in which we double your contribution. A company laptop and phone. Flexible working hours that you can arrange yourself. Hybrid working is fully supported. Fun outings with your team and the chance to challenge your colleagues to a game of table tennis, chess, or pool.