Senior Java Software Developer

As part of our ongoing growth, we are looking for a Senior Java Software Developer to join our teams and work on client projects located in Brussels. You will join our client’s application modernization initiative, focused on upgrading and modernizing a portfolio of existing Java applications running on legacy environments.

As a Senior Java Upgrade & Migration Engineer, your main responsibilities will include:

• Analyze existing Java applications running on legacy Java versions (starting from Java 7).
• Plan and execute migrations towards modern Java versions (Java 17, 21 and above).
• Identify and resolve compatibility issues related to frameworks, libraries, and application servers.
• Perform code refactoring and modernization to comply with current Java best practices.
• Troubleshoot and resolve complex technical issues during migration activities.
• Conduct impact assessments and define migration strategies for legacy applications.
• Collaborate with development teams, architects, and infrastructure experts throughout the upgrade process.
• Support testing, validation, and deployment of upgraded applications.
• Contribute to the modernization of application hosting environments.
• For part of the team, support containerization and deployment activities using OpenShift, Kubernetes, and Tomcat

• You have at least 5 years of experience in Java, spring or spring boot
• You have strong experience in Java development with expertise ranging from Java 7 to Java 21+.
• You have proven experience in large-scale Java Upgrade & Migration projects.
• You have expert-level knowledge of Java Core and enterprise application development.
• You have strong analytical skills with extensive experience in troubleshooting and resolving complex technical issues.
• You are able to assess legacy architectures and define modernization roadmaps.
• You have experience with application servers and middleware technologies.
• You have hands-on experience with Tomcat.
• Experience with OpenShift, Kubernetes and containerized environments is considered a strong asset.
• Good understanding of CI/CD and modern deployment practices.
• Strong communication and collaboration skills.
• Professional proficiency in Dutch or French, combined with good English.

• Permanent contract with an attractive salary package
• Company car with fuel card
• Representation fees
• Meal vouchers
• Mobile phone subscription
• Group insurance & healthcare insurance
• Possibility of remote work
• 20 legal vacation days + 12 compensatory days

ALTEN is a world leader in engineering and technology consulting, with over 57 000 employees in more than 30 countries. We support major companies in their innovation, R&D, and digital transformation projects across sectors such as automotive, aerospace, energy, finance, life sciences, and telecommunications.

Present in Belgium for over 25 years, ALTEN Belgium operates from its offices in Brussels and Antwerp. Today, with a team of 700 consultants ALTEN Belgium offers a wide range of expertise across Engineering, Life Sciences, and IT fields. From Automotive to Railway, and Medtech to Agrifood, our experts deploy their knowledge to provide innovative solutions in a dynamic and forward-thinking environment.