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# Backend Developer

- **Company:** Número De
- **Location:** Madrid, Spain (Remote available)
- **Salary:** €52,000.0 - €68,000.0
- **Contract:** Temporary contract
- **Skills:** Java (Programming Language), Multitier Architecture, Microsoft Azure, Code Review, Distributed Systems, Object-Oriented Software Development, Scrum Methodology, Software Architecture, Software Deployment, GitHub Copilot, Spring-boot, Backend, Event Driven Architecture, AngularJS, Kubernetes, Front End Software Development, Restful APIs
- **Published:** September 5, 2026
- **Apply:** https://www.adzuna.es/contact-us.html

## About the Role

+ 5-8 years of professional backend development experience.
 + Strong Java and Spring Boot expertise, plus relational databases and SQL.
 + Knowledge of object-oriented design, software architecture, and REST APIs.
 + Experience taking ownership of features through production deployment.
 + Advanced English communication skills (C1)
 + Based in Madrid and available for hybrid work.
 + Preferred: Azure, Kubernetes, Angular, event-driven systems, observability, modernization projects, or mentoring experience.

## Description

+ Develop and modernize backend services using Java, Spring Boot, and Hexagonal or Clean Architecture principles.
 + Own features from technical design and estimation through implementation, testing, and release.
 + Design REST APIs and integrations for distributed systems.
 + Build automated unit, integration, and acceptance tests.
 + Contribute to code reviews, architecture discussions, sprint planning, and continuous improvement.
 + Ensure performance, scalability, security, reliability, and observability.
 + Use GitHub Copilot and agentic coding tools to understand legacy services and improve delivery quality.
 + Collaborate with architects, frontend developers, analysts, testers, and healthcare specialists.