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About the Role
We’re seeking a Senior Fullstack Java Developer (Freelance) to join our client’s transformation journey in Brussels. This is a 7‑month freelance assignment where you’ll play a pivotal role in modernizing critical IT systems that underpin essential public services. Your expertise will drive the evolution from legacy to cloud‑native architectures, ensuring resilience, compliance, and future‑readiness.
Why This Role Matters
Our client is navigating a complex technological landscape, balancing legacy systems with emerging cloud and hybrid solutions. As a Senior Fullstack Java Developer, you’ll be instrumental in reducing technical debt, harmonizing architectures, and ensuring regulatory compliance (NIS2). Your work will directly impact the efficiency, security, and scalability of systems that serve millions, making a tangible difference in public service delivery.
Key Responsibilities
Design, develop, and adapt high‑performance, user‑centric IT applications for critical business domains.
Analyze technical specifications and architect optimal solutions for both legacy and modern environments.
Lead technical analysis within business projects, advising on integrations, data models, and scalability.
Champion the adoption of new technologies and architectural patterns within the team.
Resolve complex technical challenges in a highly interconnected, regulated environment.
Ensure seamless integration and coherence between legacy systems and new cloud/hybrid components.
Promote best practices in code quality, security, and compliance with NIS2 standards.
Collaborate in Agile/Scrum teams, leveraging Atlassian tools for project delivery.
Technical Skills
Expert‑level Java (Spring, Spring Boot, microservices, API‑driven, event‑driven architectures)
Front‑end frameworks: Angular or ReactJS (confirmed experience)
Containerization and orchestration: Docker, OpenShift
Relational databases: MySQL, advanced data modeling
Integration technologies: REST, GraphQL, messaging, event‑driven systems
Hexagonal Architecture (confirmed)
Hibernate/JPA (expert), Lombok (confirmed)
Build and versioning: Maven, Git, NPM
Testing: JUnit (expert)
Development tools: IntelliJ (expert), SonarQube
IBM WebSphere (confirmed)
SOAP, JSF (confirmed)
Security standards and resilient, high‑availability architectures
Very good command of French, Dutch, and English (all three required)
Other Requirements
Master’s degree in IT or equivalent professional experience
Proven experience (5‑7+ years) in complex IT programming environments
Agile/Scrum methodology (expert level)Experience with Atlassian Stack (confirmed)
Experience within a federal public service environment (junior level)
Structured, analytical, and pedagogical communication style
Autonomous, proactive, and quality‑driven mindset
Ability to connect business needs with technical solutions and maintain a global vision
Partial remote work possible after initial on‑site onboarding (2 weeks)
Contract until end of year, with potential for renewal
This is a Freelance Position
This freelance assignment is based in Brussels, with a 7‑month duration and the possibility of extension.
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