During November 2024, Sergio Garcia de la Cruz enhanced the Diagnostics subsystem in the AliceO2Group/AliceO2 repository by introducing detailed logging of TrackRefs size immediately before assertion failures. Working in C++ and applying strong debugging and software development skills, he ensured that the new logging provided actionable information for root-cause analysis without altering existing assertion semantics or introducing runtime regressions. This targeted improvement addressed the need for better observability in failing tests, streamlining the triage process in continuous integration environments. Sergio’s focused contribution delivered a practical solution that deepened diagnostic capabilities while maintaining the stability and reliability of the codebase.