Full-Stack Developer

Senior Full-Stack Developer (Frontend-focused) Contract: Long-term mission - Freelancer prefered Location: Remote (Spain-based) We're looking for an experienced frontend-leaning Full-Stack Developer to join our international technology team building financial and fintech products. You'll spend most of your time crafting polished, scalable web interfaces, while being comfortable reaching into the backend to deliver a feature end to end. This role suits someone proactive, detail-oriented, and product-minded. Your responsibilities: - Design, build, and maintain high-performance React + TypeScript web applications, from shared UI components to full product screens. - Own the front-end: state management, forms and validation, internationalization (i18n), and integration with REST/OpenAPI backends and auth (Keycloak/JWT). - Contribute to and extend a shared component library used across multiple web apps - keeping things reusable, consistent, and clean. - Reach into Java / Spring Boot microservices when a feature needs it (new endpoints, DTOs, wiring), collaborating closely with the backend team. - Collaborate with cross-functional teams (architecture, product, compliance) and contribute to technical decisions and continuous improvement. Your profile: - 5+ years as a full-stack developer, with a clear frontend focus. - Strong expertise in JavaScript/TypeScript and React (state management, component libraries, testing, i18n). Vue/Angular experience welcome, but React is our stack. - Solid experience consuming and integrating REST APIs (OpenAPI/generated clients; GraphQL a plus). - Comfortable contributing to a Java / Spring Boot backend (or a strong willingness to ramp up) - you don't need to be a backend specialist, but you shouldn't be blocked by it. - Familiarity with PostgreSQL, containerized services (Docker), CI/CD (Jenkins), and AWS. - Flutter/Dart mobile experience is a plus (we ship native apps too). - Background in financial services or fintech is a strong plus; cryptocurrency/blockchain knowledge is a significant plus. - Excellent English communication skills. - Based in Spain and available to start Immediatly. Why join us? - Work on cutting-edge financial technology - payments, KYC/KYB, cards, wallets, and crypto. - International, collaborative, agile culture. - Long-term remote engagement with flexible work arrangements. If you enjoy building great user-facing products at the intersection of finance and technology - and aren't afraid to follow a feature all the way to the API - we'd love to hear from you.