Java Technical Lead

SII Belgium is looking for a Full Stack Developer / Technical Referent to join our Service Center located on-site at one of our key clients in the Defense sector!

In this hybrid role, you'll take part in software development while also acting as a technical referent within a small and agile team working on high-security, mission-critical projects.

SII is a European digital and engineering services company of 16,000 experts. SII Belgium supports large businesses in adopting new technologies and managing innovation. We value empowerment and entrepreneurship, offering a fulfilling work environment. Our mission is to shape the future of digital products and services, while contributing to a sustainable world.

Responsabilities:

As Full Stack Developer (80%)

• Design and develop secure, high-quality applications using Java and Angular
• Perform unit and integration testing to validate functionality, performance, and security
• Write and maintain technical documentation following internal and industry standards
• Collaborate with client teams to contribute to software architecture decisions

As Technical Referent (20%)

• Support and coach junior developers through code reviews and day-to-day guidance
• Participate in monthly technical governance meetings with client stakeholders and SII management
• Help structure and optimize the service center by analyzing project activities, documenting processes, and promoting autonomy within the team

You’ll be working in a modern and secure environment using:

• Back-end: Java 17, Spring Boot
• Front-end: Angular, web authentication protocols (SAML, OpenID, OAuth)
• Integration & APIs: REST, XML, JSON
• Security: PKI, Java Cards
• DevOps & Tooling: Git, Maven, CI/CD pipelines, Docker, Kubernetes
• Infrastructure & Messaging: Linux, Kafka
• Approach: DevSecOps best practices

Requirements:

• Bachelor’s or Master’s degree in Computer Science or related field
• Minimum 5 years of experience in software development
• Solid experience with Java, Spring Boot, and Angular
• Familiarity with CI/CD pipelines, containerization, and secure coding practices
• Experience in high-security environments or the defense sector is a strong plus
• Fluent in English (French is a plus)
• Strong communication skills and willingness to support and lead technically
• Payroll only

What We Offer:

• A strategic role on a long-term project in the Defense sector
• A balanced position combining hands-on development and technical leadership
• Competitive salary and full benefits package
• Access to continuous learning, certifications, and career development
• A collaborative and supportive work culture backed by a strong international group

Ready to take the lead while staying hands-on? Apply now and Let’s Tech Together!