How application performance monitoring metrics helps developers

This post introduces GitLab Metrics, powered by Prometheus, as a component of the broader GitLab Monitoring solution. It details how GitLab Metrics integrates with Kubernetes to provide default metrics (e.g., memory usage, NGINX metrics), custom metrics via promQL queries, alerts, and custom dashboards configurable via YAML. It also explains how to integrate an existing Prometheus instance and how GitLab's infrastructure team dogfoods this capability by providing feedback to improve charting and eventually phase out Grafana.