PowerUp is a performance intelligence platform, inspired by elite sports. Just as world class athletes rely on data and coaching to reach peak performance, we help employees, teams and organisations do the same.
As PowerUp enters the next stage of our growth, we're looking for 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 also building towards an agent-first architecture, where AI becomes the primary interface for users.
What you'll do:
- Design, implement, test and maintain features end-to-end across frontend, backend, services and supporting data layers
- Build and evolve secure, scalable APIs and microservices
- Ensure robust data flow and integrations between systems, including ingestion and processing pipelines
- Contribute to architectural decisions with a focus on scalability, security, reliability and customer experience
- Implement and improve engineering processes including code reviews, test coverage, documentation and deployments
- Help set engineering standards, especially as the team grows
- Improve and extend existing systems as well as building new features - we value developers who read and understand code before rewriting it
Required:
- Proven experience in full stack development
- Strong expertise with Next.js, React & TypeScript
- Familiarity with iOs and Android mobile development (React, Native or similar)
- Solid backend experience with Node.js, python and/or Ruby
- Experience working with cloud environments (Azure strongly preferred)
- Comfortable in fast-paced, ambiguous start-up environments
- Experience writing unit and integration tests, working with CI/CD and automating deployments
- Knowledge of securing coding practice and modern API security approaches
- Excellent autonomy, ownership and communication skills in remote-first team
- Professional English (B2+)
Preferred:
- Experience with Microsoft Data Platform components
- Experience with the Microsoft Azure App Service or similar cloud web platform
- Experience integrating applications with LLM APIs (Open, Claud etc.), SLMs or building lightweight agentic workflows. Understanding of how applications feed context to AI Agents (RAG, MCP)
- Understanding of UX principles, ability to work from Figma, comfort translating user behaviour into intuitive UI
- Experience scaling systems to handle growth in users, data or traffic
- Exposure to NoSQL databases or experience supporting data migration
Why PowerUp
- Remote 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
- Opportunity to shape your career as our team and product scale
Details:
- Start date ASAP
- Valencia, Spain location. Can be elsewhere in Spain but must be available to meet in Spain or England on monthly basis, or more as needed
- Competitive salary
- Annual performance bonus
- Experience
- Required
- Languages
- English – Advanced
- Employment
- Full-time
116 Carrer de Joan Verdeguer, Poblados Marítimos, 46024, València
SaaS • 1-10 Employees
Hiring on JOB TODAY since December, 2025
PowerUp is a performance intelligence platform, inspired by elite sports. Just as world-class athletes rely on data and coaching to reach peak performance, we help employees, teams, and organisations do the same.
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