Full Stack Developer, Valencia

Full Stack DeveloperEnvíe su CV y cualquier información adicional requerida después de haber leído esta descripción, haciendo clic en el botón de solicitud.As PowerUp enters the next stage of our growth, we re now looking to hire an ambitious, motivated Full Stack Developer In this role, you ll work end-to-end across our web and mobile applications, internal telemetry pipelines, and customer-facing intelligence dashboards. You ll collaborate closely with our CTO to build secure, scalable systems that will support rapid growth - and help set the foundation for an engineering team as we expand.PowerUp is building toward an agent-first architecture where AI becomes the primary interface for users. Youll help ensure our applications can surface data to AI agents, support conversational interactions, and integrate with AI services.What you ll do:Design, implement, test, and maintain features end-to-end across frontend, backend, services, and supporting data layersBuild and evolve secure, scalable APIs and microservicesEnsure robust data flow and integrations between systems, including ingestion and processing pipelinesContribute to architectural decisions with a focus on scalability, security, reliability, and customer experienceImplement and improve engineering processes including code reviews, test coverage, documentation, and deploymentsHelp set engineering standards, especially as the team growsImprove and extend existing systems as well as building new featureswe value developers who read and understand code before rewriting itRequiredProven experience in full-stack developmentStrong expertise with Next.js, React + TypeScriptFamiliarity with iOS and Android mobile development (React, Native or similar)Solid backend experience with Node.js, python and/or RubyExperience working with cloud environments (Azure strongly preferred)Comfortable with fast-paced, ambiguous startup environments where priorities evolve quicklyExperience writing unit and integration tests, working with CI/CD, and automating deploymentsKnowledge of secure coding practices and modern API security approachesExcellent autonomy, ownership, and communication skills in a remote-first teamProfessional English proficiency (B2+ level)PreferredExperience with Microsoft Data Platform componentsExperience with the Microsoft Azure App Service or similar cloud web platform.Experience integrating applications with LLM APIs (OpenAI, Claude, Gemini), SLMs or building lightweight agentic workflows. Understanding of how applications feed context to AI agents (RAG patterns, MCP servers, function calling).Understanding of UX principles, ability to work from Figma, and comfort translating user behaviour into intuitive UIExperience scaling systems to handle growth in users, data, or trafficExposure to NoSQL databases (MongoDB) or experience supporting data migrationsWhy PowerUpRemote-first, flexible working environment.A rare opportunity to join a high-potential start-up and directly influence product, technical direction, and culture.High ownership: your ideas will meaningfully shape the company s trajectory.A team culture that values passion, autonomy, continuous learning, and collaborative problem-solving.A chance to build cutting-edge AI systems with meaningful real-world impact.The opportunity to shape your own career path as our team and product scale.Details:Start date: ASAPContract Duration: 3 months Contractor/FTE probation period with view to move into FTELocation: Valencia, SpainCompetitive salary, with bi-annual salary reviewsAnnual performance bonusHigh growth career trajectoryNext. xsgfvud js, Java, TypeScript, Python, Node.js, Ruby, Microsoft, Azure, LLMs