About the client: A German Sustainable Tech Unicorn that is redefining how general 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

📌 Senior Full-Stack Engineer (Comunidad de Madrid)
🏢 Actual Talent Spain
📍 Comunidad de Madrid