Senior Software Engineer

Legal AI is only as good as the knowledge behind it. At Lefebvre Sdu, we've been building that knowledge for over 200 years. Day in, day out. Law by law. Word by word. As the Dutch heart of Lefebvre Group, the European leader in legal and tax knowledge, we're also developing our own platform: GenIA-L, where lawyers and tax advisors don't just get an answer, but an answer they're willing to attach their name to. More than 75,000 professionals use it daily, generating over 100 million euros in ARR across Europe. We're looking for a Senior Software Engineer to help build that. HOW YOU'LL MOVE US FORWARD We're bringing separate knowledge portals together into one platform, with AI as the primary way users interact with our platform. We're building GenIA-L: an agentic AI solution that understands and answers legal questions based on our own, trusted content. With you on board, the team will be able to take end-to-end ownership of its own components. In practice, the role is backend-first: you'll take ownership of business-critical Node.js services around authentication, authorization, and user management, along with components like PDF export and chat delivery via Redis. Ownership in this role at Lefebvre Sdu means actively driving continuous improvement, stabilization, and simplification of these systems: so you won't just be keeping the lights on. Frontend work will also come up, so a solid frontend level is desired. The product is under active development, so what you build and improve now will determine how stable and scalable this platform is a year from now. WHAT WE'RE LOOKING FOR Technical depth is a non-negotiable. You have extensive experience with TypeScript and Node.js , preferably with authentication and authorization systems in production environments, as this is the most important part of the role. You're well-versed in OAuth 2.0 / OIDC flows and aren't afraid to untangle complex system integrations around permissions and roles. You take ownership: you're comfortable with stakeholder management and proactively drive improvement, simplification, stabilization, and documentation. Frontend doesn't need to be your greatest strength, but you should be good enough at it to pick it up from time to time. TypeScript / Node.js and related frameworks (e.g., NestJS, Koa) Authentication and authorization (OAuth 2.0 / OIDC) GraphQL / Apollo Relational databases (Postgres, SQLite, MariaDB) and Firebase Redis Docker, CI/CD (GitHub Actions) AWS / Kubernetes / Helm is a strong plus Familiarity with ORMs (e.g., Prisma, MikroORM) Familiarity with React / Next.js WHAT YOU'RE SIGNING UP FOR At Lefebvre Sdu, you'll work in an organization that's in the middle of a transformation and takes the public market seriously. That's the direction, and we're making the journey together. You'll get the mandate, the space, and the colleagues to make it happen. You'll join a team with a Product Owner, three frontend developers, a UX…