ROLE OVERVIEW We are seeking a Senior Software Engineer to implement and maintain backend and frontend services supporting the Contract & Billing domain of a federated data space middleware. The engineer will work closely with the Software Architect to evolve existing services, implement new capabilities, and ensure operational stability of business-critical workflows. Profile Autonomous senior engineer Pragmatic problem solver Strong ownership mindset KNOWLEDGE AND SKILLS Following skills and knowledge are required for the performance of the above listed tasks: Develop and maintain backend and frontend services supporting contract and billing workflows Implement billing logic, transaction handling, and integrations Maintain API interfaces and service contracts Ensure high test coverage and system reliability Support integration with data space connectors and external services Troubleshoot production issues and improve observability Required Skills Core Engineering 8+ years backend software development experience Strong proficiency in Java (SpringBoot preferred) Experience with a frontend framework (Angular preferred) Experience with REST APIs and service integration Experience with automated testing (unit & integration) Domain Expertise (Required) Understanding of data space concepts Knowledge of Eclipse Dataspace Connector (EDC) Experience integrating eSignature solutions Familiarity with eInvoicing processes or platforms Experience with Scrum/Agile methodologies Experience with Atlassian suite (Jira, Confluence)