Prometheus + Grafana

Prometheus and Grafana are the default observability stack for Kubernetes environments and the most widely deployed monitoring combination in cloud-native infrastructure. Prometheus's pull-based metrics collection, multi-dimensional data model (labels on every metric), and PromQL query language have become the industry standard — even AWS CloudWatch and Azure Monitor now export Prometheus-format metrics. Grafana provides the visualization layer with dashboards, alerts, and increasingly (via Grafana Loki and Tempo) logs and traces. The architecture that most teams implement wrong: running a single Prometheus instance at scale. The correct pattern uses Thanos or Cortex for long-term storage and multi-cluster federation.