Back-End Developer, Brussels (near-site) – European Commission

Back-End Developer, Brussels (near-site) – European Commission

Profile: Back-End developer with expertise in Java <17.

Minimum experience: 17 years in IT.

Duration: 400 days – Initial contract 100 days.

Studies required: Bachelor’s Degree in IT or a related field.

Language: English (C1) MANDATORY. English C2 is desirable.

Location: Brussels (near-site).

DESCRIPTION:

We are seeking an experienced Back-End Developer to contribute to the design, development, and optimisation of high‑quality server-side applications within a large-scale, international environment. The role involves building robust APIs, implementing core business logic, managing databases and server infrastructure, and ensuring strong security and data protection practices. You will collaborate closely with front-end teams, lead technical components when needed, and help drive the creation of scalable, secure, and high-performing software solutions. This position is ideal for a seasoned professional with deep expertise in modern back-end technologies, microservices architecture, and DevSecOps practices.

Tasks:

· Development of back-end website applications.

· Integration of user-facing elements developed by a front-end developer with server-side logic.

· Implement core business logic.

· Creation of servers and databases for functionality.

· Design and implementation of data storage solutions.

· Understanding and implementation of security and data protection.

· Optimization of the application for maximum speed and scalability.

· Design and develop APIs.

· Participating in the design and creation of scalable software.

· Taking lead on projects, as needed.

· Maintenance of code integrity and organisation.

· Writing clean, functional code on the back-end.

· Compile and analyse data, processes, and codes to troubleshoot problems and identify areas for improvement.

· Testing and fixing bugs or other coding issues.

· Meet both technical and consumer needs.

· Write technical documentation.

Mandatory minimum requirements:

· Bachelor’s Degree in IT or a related field.

· At least 17 years of experience in IT.

· At least one year of expertise in back end: Vert.x, Kotlin, Java (> 17) , Spring Boot (WebFlux), Hibernate.

· At least one year of expertise in Architecture & Integration: Microservices Architecture, API-driven Development, AS4.

· At least one year of expertise in Database: MongoDB, PostgreSQL, Virtuoso Triple Store, OpenSearch.

· At least one year of expertise in Containerization & Orchestration: Docker, Kubernetes.

· At least one year of expertise in Security: OpenID Connect, OAuth2, TLS, Keycloak.

· At least one year of expertise in Security Testing & Dependency Management: SAST, DAST, Fortify, SonarQube, Sonatype, Dependency-Track, Maven.

· At least one year of expertise in Collaboration & Productivity Tools: JIRA, Confluence, Office 365, SharePoint.

Additional desirable requirements:

· Ability to apply high quality standards to all tasks.

· Ability to participate in multi-lingual meetings, good communication skills.

· Capability of working in an international/multicultural environment, rapid self-starting capability and experience in working in a team, understanding the needs, objectives, and constraints of those in other disciplines and functions.

· Ability to adapt to unplanned changes or decisions.

· Ability to understand, speak and write in English C2.

· High degree of discretion and integrity is required.

Language:

· English (C1) MANDATORY. English C2 is desirable.

Location:

· Brussels (near-site).

Rate:

· 390-410€/day.