Senior Java Developer

Description

Java FX Kafka Spring Published on 01/09/2026 CDI / SII Spain East **MISSION** ----------- * Participate in the progressive migration of applications from Java 8 to Java 25\. * Perform development, fixes, and refactorings to ensure compatibility with new JVM versions. * Identify and resolve incompatibilities arising from the evolution of the Java language and platform. * Ensure temporary coexistence between Java 8 components and newer versions. * Design and maintain the build architecture of the mono\-repository, working with Maven and Gradle. * Manage cross-cutting dependencies, compilation scopes, and optimization of build processes and pipelines. Technically lead the migration from Tomcat 8 to Tomcat 9* Tomcat 10\. * Collaborate with Platform teams to align infrastructures and execution environments. * Support the transition to Jakarta EE and resolve associated incompatibilities. * Define, together with QA, the validation and non-regression strategy. * Participate in test automation and incident resolution during testing campaigns. **PROFIL** ---------- * Extensive experience as a Java developer and in technological migration projects. * Advanced expertise in Java 8, 17, 21, and 25\. * Solid experience with Maven, Gradle, and Spring Boot. * Excellent understanding of the JVM's internal workings and version-to-version compatibility issues. * Experience with multi\-module architectures and complex mono\-repositories. * Extensive experience with Tomcat, especially migrations among versions 8, 9, and 10\. * Experience working in CI/CD environments. * Strong analytical skills, autonomy, and ability to coordinate cross-functionally with technical teams. **NOTRE AGENCE** ---------------- We are a French multinational delivering IT services and solutions worldwide, present in 21 countries with over 16,000 professionals. If you wish, you can benefit from geographical mobility and participate in large-scale international projects. Our mission is to create innovative projects that simplify our clients' lives by hiring top-tier professionals and ensuring they feel fully fulfilled in their work. **GROUPE SII** -------------- At SII Group Spain, we address diverse industry needs through Digital, IT, and Engineering Services and Solutions. We combine IT and software development expertise with capabilities in manufacturing engineering, systems, mechanics, electronics, and embedded systems—delivering comprehensive solutions that drive digital transformation and innovation, aligned with our strategic pillars: Growth, People \& ESG. We aim to be the best place to work—a recognition supported by our Great Place to Work certification for the fourth consecutive year, based on positive feedback from our professionals regarding credibility, respect, honesty, pride, and camaraderie. \#LI\-XM1