Backend Developer

About the role

UST, a global digital technology services leader, is seeking a Backend Developer to join its Madrid office. You will work on large‑scale, service‑oriented solutions for enterprise clients, collaborating with cross‑functional teams in a hybrid environment.

Key responsibilities

• Design, develop and maintain backend services using Java (Spring Boot) or .NET Core.
• Implement and consume RESTful APIs following architectural standards.
• Write unit and integration tests and ensure code quality.
• Collaborate with QA, frontend, DevOps, architects and product stakeholders.
• Participate in agile ceremonies such as refinement, planning and delivery.
• Support production applications, troubleshoot issues and monitor logs.
• Contribute to continuous improvement of development practices and tooling.

Required profile

• Proven experience in enterprise backend development.
• Strong problem‑solving abilities and ownership mindset.
• Comfortable working in regulated, complex environments.
• Excellent communication skills and fluency in English.

Required skills

• Java
• Spring Boot
• .NET Core
• ASP.NET Core
• RESTful API design
• SQL (Oracle, SQL Server or equivalent)
• Git version control
• Unit and integration testing
• Agile methodologies (Scrum/Kanban)
• Basic CI/CD and DevOps concepts
• Logging, error handling and monitoring

What we offer

• 23 days of annual leave plus discretionary holidays.
• Health care plan, internet connectivity, life and accident insurance.
• Flexible benefits (meals, transport, online English lessons, etc.).
• Access to training platforms and clear career progression.
• Option to receive referral bonuses.
• Choice of 12 or 14 salary payments per year.