Java Developer

SII Group Spain provides digital, IT, and engineering services and solutions to industries across the world. It combines IT and software development expertise with manufacturing, systems, mechanical and electrical engineering, and embedded systems capabilities to support digital transformation and innovation.

• Participate in the gradual migration of applications from Java 8 to Java 25
• Develop, fix, and refactor code to ensure compatibility with newer JVM versions
• Identify and resolve incompatibilities caused by changes to the Java language and platform
• Ensure temporary coexistence between Java 8 components and newer versions
• Design and maintain the monorepository build architecture using Maven and Gradle
• Manage cross-cutting dependencies and compilation scopes, and optimize build processes and pipelines
• Lead the technical migration from Tomcat 8 to Tomcat 9 and Tomcat 10
• Collaborate with Platform teams to align infrastructure and runtime environments
• Support the transition to Jakarta EE and resolve related incompatibilities
• Define the validation and regression testing strategy with QA
• Participate in test automation and resolve issues during testing campaigns

• Extensive experience as a Java developer and on technology migration projects
• Advanced knowledge of Java 8, 17, 21, and 25
• Strong experience with Maven, Gradle, and Spring Boot
• Excellent understanding of JVM internals and compatibility issues between versions
• Experience with multi-module architectures and complex monorepositories
• Extensive experience with Tomcat, especially migrations between versions 8, 9, and 10
• Experience working in CI/CD environments
• Analytical skills, autonomy, and ability to coordinate across technical teams

• Indefinite-term contract
• Geographic mobility opportunities and participation in large-scale international projects