We are seeking a skilled and experienced Java Back-End Developer to join our team on an on-site assignment at the European Commission in Brussels. This is an exciting opportunity to contribute to high-impact, scalable digital solutions at the heart of the EU. As part of a multidisciplinary team, you will be involved in the full development lifecycle of secure and scalable applications supporting complex business processes. You’ll work in a multicultural, fast-paced environment with a high degree of autonomy and responsibility. Key Responsibilities Design, develop, and maintain robust and scalable back-end applications Implement core business logic and application functionality Create and manage servers and databases ensuring data integrity and performance Ensure security best practices and data protection compliance Collaborate with front-end developers for cross-platform optimization and integration Develop and document RESTful and SOAP APIs Lead and contribute to the design of scalable software architectures Maintain clean, functional, and well-documented code Perform code analysis, troubleshoot, and identify areas for improvement Conduct unit testing, fix bugs, and ensure overall system reliability Produce and maintain comprehensive technical documentation Participate in project meetings with technical and non-technical stakeholders Take the lead on specific projects or modules, when required Required Qualifications Bachelor’s degree (EQF Level 6) in Computer Science, Software Engineering, or other IT-related field At least 10 years of professional experience in a similar back-end development role Technical Skills (Required) Java 8+ (professional-level experience) Java Frameworks: Spring, Spring Boot, Hibernate, Java EE API Development: REST, SOAP, OpenID Connect, OAuth2, API Gateway configuration Oracle RDBMS, experience in database performance tuning Messaging systems : Kafka, JMS, ActiveMQ Web servers : Oracle WebLogic, Apache Security protocols : SSL/TLS, reverse proxy configuration Cloud services : Amazon Web Services (AWS), microservices architecture, cloud-native development CI/CD tools : Bamboo, Git Testing tools : SOAPUI, ReadyAPI, Postman Containerization : Docker Basic familiarity with NoSQL databases (e.G. MongoDB) is a plus Understanding of Agile/Scrum methodologie Soft Skills Strong analytical and problem-solving skills Excellent organizational and time management skills Ability to work autonomously as well as part of an international team Strong attention to detail and code quality Effective communication skills in multicultural and multilingual environments Proven collaboration and mentoring abilities Languages English: Minimum B1 level (oral and written) – required French: Minimum C1 level – desirable Nice to Have Familiarity with Kubernetes or other orchestration tools Experience with front-end frameworks such as Angular, TypeScript, HTML/CSS Previous experience in public sector or EU institutions environments Benefits : Private insurance Unlimited free access to wellness workplace support platform A dynamic challenging environment resulting in continuous learning / education / progression Ability to work with cutting edge technologies Pleasant working environment UpcoMinds is a dynamic IT company with 28 years of experience that provides end-to-end web and mobile solutions helping businesses to reinvent themselves in the digital world. Our team’s skills and expertise will ensure the holistic digital transformation of any organization, which will considerably improve both business operations and customer’s experience. Our goal is to always have our end products and services reflect our deep engineering skills and elegant progressive design aesthetic. We fundamentally believe deeply in developing long term strategic partnerships with our clients by exceeding expectations and maintaining a high level of transparency. Find out more about us at We commit to promote Inclusion & Diversity by creating a working environment where all employees are treated with dignity and respect and where individual differences are valued. We offer equal opportunity in all aspects of employment. Our recruitment consultants will go through your Curriculum Vitae as soon as possible and get back to you to discuss the opportunity for which you apply. If you don’t hear from us in the coming ten (10) working days, you may consider that you have not been selected for the particular job. Your CV will be retained for two years in accordance with GDPR regulations.