Senior Full-Stack Engineer (Node.js/React) – Sustainable Tech Unicorn

Senior Full-Stack Engineer (Node.js/React) – Sustainable Tech Unicorn As a Senior Full-Stack Engineer you will be an architect of transparency. You will own the end-to-end development of products that help over 2,000 global companies comply with critical ESG regulations Apply Actual Talent is the talent acquisition consultancy that offers Executive Search, RPO and Talent Solutions. About the client: A German Sustainable Tech Unicorn that is redefining how global corporations handle transparency. Backed by a €130M Series C investment, our client has built a proprietary, serverless cloud infrastructure to ensure human rights and ecological responsibility across global supply chains. Currently in a massive consolidation phase, their Madrid Hub is expanding from 20 to over 100 top-tier engineers in 2026. This is your chance to join a high-growth environment where engineering quality and product ownership are the top priorities. The Mission: Impact at Scale As a Senior Full-Stack Engineer you will be an architect of transparency. You will own the end-to-end development of products that help over 2,000 global companies comply with critical ESG regulations (LkSG, CSDDD). Key Responsibilities: System Architecture: Design and optimize scalable full-stack features, focusing on robust backend systems and high-performance frontend interfaces. Infrastructure Innovation: Work directly on a custom-built, serverless cloud ecosystem (the Hub). Technical Leadership: Influence the design of core libraries and microservices architecture used worldwide. Collaborative Strategy: Work in high-density agile squads (4-6 people) alongside tech leads to define the product roadmap. Quality Advocacy: Drive technical excellence through rigorous code reviews, automated testing, and CI/CD best practices. Your Profile:e Experience: 6+ years of professional experience in Full-Stack development, specifically within product-based companies (no agencies or consultancies). Backend Mastery: Expert-level command of Node.js and TypeScript . Frontend Proficiency: Strong experience with React.js . Architecture Mindset: Deep understanding of microservices, end-to-end product ownership, and scalable design patterns. Communication: Fluent English (C1). Spanish is a plus but not mandatory for technical collaboration. What’s in it for you? Unlimited Growth: Join a unicorn at the peak of its global expansion with a direct line to leadership. Good Salary Package Hybrid Work: A balanced model of 3 days in the Madrid office / 2 days remote Premium Benefits: €80/month via Thanksben + up to €200/month for transport and meals. High-Performance Culture: A world-class engineering team where technical decisions are made by developers, for developers. Department IT & Telecom & Media Role Engineering Locations Madrid Remote status Hybrid