Senior Full Stack Developer (Freelance) - 12 months - Belgium

Where Builders Build the Future

At RELYzIT Talent, we don’t recruit — we build. We unite the top 2% of builders — engineers, architects, creators — into a movement across Europe and the GCC. Vetted through our VECTOR7™ Signal Stack, you’re not just hired, you’re chosen. This is more than work. This is where builders build the future.

About the Role

Our client is driving a major digital transformation, modernizing and securing the business applications that power public services for millions. As a Senior Full Stack Developer, you’ll join a multidisciplinary Agile team to create, evolve, and safeguard critical web applications that directly impact both administration and citizens. This is a freelance opportunity for 12 months, based in Belgium, where your expertise will shape the digital backbone of tomorrow’s public sector.

Why This Role Matters

The mission is clear: build and maintain robust, secure, and scalable web applications that are essential to public service delivery. You’ll be at the heart of a new application maintenance hub, ensuring that digital tools remain modern, high-performing, and secure. Your work will directly influence the efficiency, reliability, and user experience of applications used by thousands daily — making a tangible impact on society.

What You’ll Be Doing

• Designing, developing, and deploying full stack web applications using Angular, TypeScript, HTML5, CSS/SASS (front-end) and Java (Spring or equivalent), PHP (back-end).
• Building application components, web pages, and REST APIs that meet both functional and non-functional requirements.
• Driving all phases of the software development lifecycle: from design and development to testing, integration, and production deployment.
• Ensuring corrective and evolutionary maintenance, resolving anomalies, and continuously improving existing applications.
• Collaborating closely with UX/UI, testers, project managers, and analysts to translate business needs into robust technical solutions.
• Conducting technical analysis of requests and proposing innovative, pragmatic solutions.
• Defining, implementing, and evolving data models using relational databases (SQL, MySQL, PostgreSQL).
• Implementing and optimizing service-oriented architectures for performance, security, and maintainability.
• Championing code quality, maintainability, performance, and application security through best practices and rigorous testing (unit and end-to-end).
• Participating in code reviews and continuous improvement initiatives for development practices.
• Providing technical support to fellow developers and business teams.
• Ensuring integration with existing design systems and adherence to graphic standards.

Technical Skills

• Java back-end development (Spring or equivalent) – Senior
• PHP back-end – Confirmed
• Front-end Angular / TypeScript – Confirmed
• REST Architectures – Confirmed
• Containerization (Docker/Kubernetes) – Confirmed
• Dependency management tools (Maven, NPM, Composer) – Confirmed
• Version control tools (Git, GitLab) – Confirmed
• CI/CD Pipelines (Jenkins, GitLab) – Confirmed
• SQL / PostgreSQL – Confirmed
• Unit tests and software quality (JUnit, Playwright) – Senior

What We’re Looking For

• Proven experience as a Senior Full Stack Developer in complex, mission-critical environments.
• Ownership mindset: you take initiative, drive outcomes, and proactively propose improvements.
• Strong problem-solving skills and a pragmatic, solution-oriented approach.
• Excellent communication and collaboration skills within multidisciplinary Agile teams.
• Openness, motivation, and a passion for continuous learning and improvement.
• Sensitivity to user experience (UX) and a commitment to delivering high-quality solutions.
• Experience working in Agile/Scrum environments is a plus.
• Self-organization and the ability to manage priorities in a dynamic context.

Language Proficiency

• Professional proficiency in English is required.
• Knowledge of French or Dutch is a plus.

Other Requirements

• Partial remote work is possible; on-site presence in Belgium required as per project needs.
• Successful candidates will be invited to a technical interview (remote if necessary) as part of the VECTOR7™ Signal Stack vetting process.

Ready to build the future? Upload your CV and join the movement of elite builders at RELYzIT Talent.

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