Worked on backend development and logging enhancements for the sklintyg/webcert and sklintyg/core repositories using Java. Focused on improving observability in the CS integration path by enabling tracing and enhanced logging through the introduction of TRACE_ID_KEY and SESSION_ID_KEY imports, which improved diagnosability and laid the foundation for faster incident response. Addressed logging consistency by resolving import-related issues, ensuring stable integration logs. Additionally, delivered a targeted localization fix in sklintyg/core by correcting the FK7426 certificate model name, adding the missing Swedish word ‘år’ to improve user-facing clarity while maintaining data integrity and backward compatibility. Demonstrated attention to traceability and maintainability.