.NET Fullstack Engineer (f/m/d)
Apply for .NET Fullstack Engineer (f/m/d) at Axpo group in Madrid, MD, ES. Full-time on-site position offers great opportunities for career growth. Energy trading moves fast, and the tools behind it need to keep up. You’ll become the go-to person for a complex, business-critical application at the heart of Axpo’s energy trading operations. You’ll start by working alongside external developers to deeply understand the system and its business logic, then progressively take ownership — delivering change requests, supporting users and driving technical improvements. Over time, you’ll modernize legacy logic into clean .NET code, improve test coverage and help evolve the frontend. This is hands-on, technical work on a real system with real users.
Tasks and Responsibilities
- Learn, document and internalize application logic and business rules currently held by external developers.
- Deliver change requests, bug fixes and small features to continuously add business value.
- Provide L1/L2 support: assess and prioritize reported issues, diagnose root causes,



implement fixes or workarounds.
- Design and develop ASP.NET Core APIs and background services.
- Maintain and evolve the frontend (Angular).
- Ensure quality through automated testing and solid CI/CD practices.
- Collaborate with analysts, architects and engineers to plan and deliver iteratively.
- Use AI-assisted tools (LLMs, Copilot) to accelerate development and refactoring.
- Contribute to technical documentation and architectural decisions.
- Over time, rearchitect and modernize application components, bringing business logic into clean, testable .NET code.

Qualifications
- Education: University degree in Software Engineering or a quantitative subject.
- Must-have: 5+ years of experience with C#/.NET (ASP.NET Core, RESTful APIs); strong OOP and clean code practices.
- Solid SQL skills — comfortable working with complex queries, stored procedures and database logic.
- Experience with

📌 .Net Fullstack Engineer (España)
🏢 Axpo Group
📍 España