Backend Developer (Java or .NET) (Madrid)

UST is looking for a Backend (Java or .Net) Developer.

Location: Madrid (hybrid: 3 days in the office, 2 days remote per week). CV Language Requirement: English.

Responsibilities

• Design, develop, and maintain backend services in a distributed, service‑oriented architecture.
• Implement and consume RESTful APIs aligned with established architectural standards.
• Develop backend software using Java (Spring Boot) or .NET Core, depending on the product stack.
• Implement and maintain unit and integration tests as part of the development lifecycle.
• Collaborate closely with QA engineers, frontend developers, DevOps, architects, and product stakeholders.
• Participate actively in refinement, planning, development, and delivery activities.
• Ensure code quality, maintainability, and consistency across the backend codebase.
• Support applications running in production, including troubleshooting and analysis of ...