AI Builder (.NET)

Job description

We built NET4, the workforce management ERP used by nearly half of all staffing agencies in Spain, and NIA, our own suite of AI agents. We are now building a software factory where agents write the code and people design, specify and verify it. We are looking for three AI Builders who want to build it with us from the inside.

Your tasks

• Develop projects with Claude Code, from specification to pull request
• Prepare the context for each project (agent documentation, conventions, subagents, MCP servers) so agents work reliably
• Verify that the generated code is correct through automated testing, so that manual review is not the only safeguard
• Analyse why an agent fails, then fix the process, the context or the specification
• Maintain and improve the factory’s reusable skills and templates
• Propose ongoing improvements to how we work with agents

Your profile

• At least 3 years as a software developer, with a solid understanding of architecture and good practices
• Experience with C# / .NET (ASP.NET Core, Entity Framework) and SQL Server
• Real, intensive use of coding agents (Claude Code, Cursor, Copilot Agent or similar) on professional projects. In the interview, we will ask you to show us how you work
• Strong focus on testing: unit, integration and end-to-end tests (xUnit or NUnit, Playwright or similar)

• Azure services (App Service, Functions, Azure SQL)
• Experience with Spec-Driven Development
• Knowledge of ERP, payroll or HR management
• Working proficiency in English

Your benefits

• Permanent, full-time contract

• Working hours: Monday to Thursday 09:00-17:30, Friday 08:00-15:00. From June to September, 08:00-15:00 every day
• Daily work with the most advanced AI tools, with a budget to use them
• Ongoing training in agent-based development and support from day one
• Health insurance
• A solid company with its own product, and a close, professional team where your ideas get put into practice