Worked on the prometheus-community/helm-charts repository to deliver an upgrade of the kube-prometheus-stack to prometheus-operator v0.91.0, focusing on improving the reliability and maintainability of PrometheusRule resource validation. Enhanced the admission webhook by introducing PromQL validation options, which help detect misconfigurations earlier in the deployment process and reduce friction during upgrades. Leveraged DevOps practices and expertise in Kubernetes, Helm, and Prometheus, with changes implemented primarily in YAML. Maintained clear traceability through detailed commit references and aligned release notes, ensuring downstream users benefit from upstream features and fixes while supporting smoother, more reliable upgrade workflows.