Backend Java Developer

Title: Java Backend Engineer

Location: Brussels, Belgium

Duration: 6 months

Mode: Hybrid

Languages: French & English

Job Description

As a Senior Backend Developer you will:

• Design, build, and maintain scalable backend services, databases, and APIs supporting complex data-exchange and regulatory compliance requirements.
• Develop server-side logic that enables secure registration, validation, and publication workflows for software products and digital applications.
• Implement robust data storage, transformation, interoperability, and logging mechanisms aligned with mandated technical specifications.
• Integrate backend components with user-facing systems and ensure high performance, reliability, and fault tolerance.
• Ensure strong security, authentication, and authorisation controls, including protection of sensitive electronic data.
• Conduct testing, debugging, and optimisation of backend components; analyse system behaviour to improve performance and code quality.
• Produce high-quality technical documentation, including API specifications and operational guidelines.
• Collaborate in iterative development cycles, support deployment activities, and provide technical leadership when required.

Qualifications

What would make you a fit for the role:

• Master’s or Bachelor’s degree with at least 10 years of relevant experience
• Experience in developing back-end solutions using Vert.x, Kotlin, Java 17+, Spring Boot (WebFlux), and Hibernate.
• Professional experience in designing and implementing microservices architecture, API-driven development, and AS4 integration.
• Proficiency in working with MongoDB, PostgreSQL, Virtuoso Triple Store, and OpenSearch for efficient data storage and retrieval.
• Hands-on experience with Docker and Kubernetes for deploying and managing applications in scalable environments.
• Knowledge in implementing secure systems using OpenID Connect, OAuth2, TLS, and Keycloak.
• Experience with SAST, DAST, Fortify, SonarQube, Sonatype, Dependency-Track, and Maven to ensure code quality and manage dependencies.
• Proficiency in using JIRA, Confluence, Office 365, and SharePoint to support teamwork, project management, and documentation.
• Fluency in English, with knowledge of French considered an additional advantage.