Senior Java Migration Engineer (Tech Lead Migratie)

Role & Context

For large-scale legacy migration and version upgrade projects, we are looking for a Senior Java Migration Engineer who will take the technical lead.

You will work on large Java EE platforms running on WebLogic, consisting of numerous applications, screens, and batch processes. From a functional perspective, the applications will remain unchanged, but technically, a significant transformation will take place: from Java 8 to Java 21, from Java EE to Jakarta EE 10, and, where relevant, a migration to Quarkus 3. In some projects, this will also be combined with a Vaadin migration.

As Tech Lead, you will take architectural ownership of the migration journey. You will help define the technical direction, safeguard architectural and technical decisions, and ensure the team migrates the different applications in a consistent and high-quality way.

What will you do?

• Prepare a technical analysis and migration approach for each application, supported by an architect.

• Document key technical decisions in Architecture Decision Records (ADRs).

• Help determine for each application whether a WebLogic upgrade is sufficient or whether a migration to Quarkus is the preferred option.

• Take the technical lead on one or more pilot applications and translate the lessons learned into subsequent migrations.

• Use and evaluate migration tooling, determining where automation is sufficient and where manual remediation is required.

• Help safeguard the acceptance criteria, including regression testing, test coverage, and critical business flows.

• Provide technical guidance and coaching to junior and medior team members throughout the migration journey.

Your Technical Toolkit

For this role, we are looking for someone who not only has strong Java expertise, but also understands the complexity of enterprise environments and large-scale technology upgrades.

Must-have

• Extensive experience with Java EE/Jakarta EE on WebLogic, including EJB, JMS, JTA/XA, and JNDI.

• Strong Java expertise, from Java 8 through Java 21/25, including common upgrade and compatibility challenges.

• Knowledge of Jakarta EE 10 and the transition from javax to jakarta.

• Familiarity with Quarkus 3 and a solid understanding of how it differs from a full-fledged Java EE application server.

• Experience writing ADRs and technical analyses.

• Experience with Maven.

Nice-to-have

• Experience with large-scale legacy migration projects.

• Knowledge of container platforms and AWS.