Junior Full Stack Developer

Junior Full Stack Developer - 4 months - Brussels, Belgium At RELYzIT, we don't recruit — we build. We unite exceptional builders: engineers, architects, creators, across the BENELUX and the GCC. Vetted through VECTOR7™'s multi-signal evaluation, you evaluate once and carry that credential forever. This is more than work. This is where builders build the future. About the Role RELYzIT Talent is seeking a Junior Full Stack Developer for a high-impact freelance assignment with our client, supporting the CIAO Catena program. This mission is at the heart of digital transformation for public sector organizations, driving the development, integration, and evolution of secure, scalable, and interoperable digital services. As a builder, you will help shape the future of public administration, ensuring seamless collaboration and information exchange across organizations. Why This Role Matters The CIAO Catena initiative is pivotal in modernizing public sector digital infrastructure. Your work will directly contribute to the creation and enhancement of business-critical applications and shared services, enabling public organizations to deliver better, more resilient digital experiences. This is your opportunity to make a tangible impact on society, working on solutions that matter at scale. Key Responsibilities • Develop and maintain business applications and shared digital services in a collaborative, Agile environment. • Design and implement application components, APIs, and web services using modern Java and Spring technologies. • Contribute to application architecture and technical building blocks alongside technical leads and solution architects. • Participate in technical workshops, Agile/Scrum ceremonies, and stakeholder meetings to align on requirements and solutions. • Support testing, technical documentation, deployments, quality assurance, monitoring, reporting, and continuous improvement initiatives. • Integrate with internal and external systems via APIs and service-oriented architectures. • Ensure adherence to security, performance, interoperability, and quality standards throughout the software lifecycle. • Collaborate with multidisciplinary teams to deliver robust, scalable, and secure digital services for the public sector. Technical Skills • Java (11, 17, and 21) and Spring Framework (Core, JDBC, Data, Security, AOP) • Spring Boot 2.x and 3.x • JPA / Hibernate • RESTful Web Services, OpenAPI / Swagger • Angular (17 and 20) • Keycloak, Lombok, MapStruct • SOA, Backend-for-Frontend, CQRS • Test-driven development (JUnit, Mockito, Spring Test, Cypress) • Maven, Docker, OpenShift / Kubernetes • Git, GitLab CI/CD, SonarQube • NPM, OAuth 2.0 • Flyway or Liquibase • PostgreSQL, SQL Server, Oracle, and relational databases • BPMN and UML • Jira and Confluence • Weblogic • Continuous Integration and Continuous Delivery (CI/CD) Language Proficiency • French or Dutch: Expert level required • English: Working proficiency Other Requirements • Minimum 3 years of professional experience in Java software development • Experience in complex, multi-system environments and large-scale digital transformation projects • Experience in public sector environments is a plus • Proven experience in Agile/Scrum delivery environments • Strong analytical and problem-solving skills • Ability to quickly understand and maintain existing codebases • Customer and solution-oriented mindset • Team player with strong communication skills • Autonomous, proactive, and quality-focused • Hybrid working environment; regular on-site presence may be required • Collaboration with multidisciplinary teams across public sector organizations • Long-term assignment with potential for extension based on project evolution About the VECTOR7™ Signal Stack All RELYzIT Talent builders are vetted through VECTOR7™'s multi-signal evaluation process. This ensures you are recognized for your expertise and carry a credential that sets you apart — evaluated once, trusted everywhere. Freelance Opportunity This is a freelance position for an initial duration of 4 months, based in Brussels, Belgium, with partial remote flexibility. RELYzIT Talent is committed to placing elite tech talent in roles that drive real impact and innovation. Ready to build the future with us? Upload your CV now and join a community where builders lead the way.