In December 2024, Berger developed a feature for the kamailio/kamailio repository that enhanced Prometheus monitoring capabilities within Kamailio. He introduced the xhttp_prom_tags parameter to the xhttp_prom module, enabling users to attach custom tags and labels to Prometheus metrics for more granular and flexible observability. Working primarily in C and leveraging his expertise in system programming and monitoring, Berger ensured the new functionality maintained backward compatibility with existing Prometheus integrations. This targeted update addressed the need for finer-grained metric reporting, allowing operators to gain deeper operational insights without disrupting established monitoring workflows or requiring major configuration changes.