Prometheus + Grafana: The Monitoring Stack That Replaced Our $40K/Year Tool

We were paying $40K/year for a SaaS monitoring tool. It ingested metrics, showed dashboards, and sent alerts. It also had a 45-second query latency, a 200-metric cardinality limit per service, and a sales team that called every quarter to upsell. We replaced it with Prometheus + Grafana in 3 weeks. Our query latency dropped to under 2 seconds. We now track 500+ metrics. Total cost: the compute to run it — roughly $200/month on AKS. Here's the complete setup. Why Prometheus Wins for Kubernetes Prometheus was built at SoundCloud in 2012 specifically for monitoring dynamic, containerized environments. It's not a general-purpose database — it's a time-series database optimized for operational metrics. Three things make it ideal for Kubernetes: 1. Pull-based model. Prometheus scrapes targets at regular intervals. In Kubernetes, it discovers targets automatically through service discovery. When a new pod starts, Prometheus finds it. When it dies, Prometheus stops scraping. No agent installat