Used For

• +**Your team spends 2 hours a day SSH-ing into servers to check if things are broken** → Prometheus scrapes everything automatically every 15 seconds, shows CPU and memory in dashboards
• +**Database problems take 4 hours to debug because you're flying blind** → MySQL monitoring shows exactly which queries are slow and when they started acting up
• +**Kubernetes pods crash and you find out from angry users** → Auto-discovers all containers, alerts when CPU hits 80% before users notice
• +**Alert floods during outages make everything worse** → Groups related alerts into one notification instead of 47 Slack messages
• +Multi-dimensional data lets you slice metrics by region, environment, or any label you want

Best For

• >Your current monitoring dies whenever you actually need it most
• >Running Kubernetes and tired of SSH-ing into 50 pods to check CPU usage
• >You've got DevOps engineers who can handle YAML configs and don't mind maintaining servers

Not For

• -Teams under 10 people — you'll spend more time maintaining it than it saves you
• -Anyone wanting a hosted solution — this is self-run only, no SaaS option exists
• -Non-technical teams who just want dashboards — requires coding to expose metrics from your apps

Pairs With

• *Grafana (where you'll build actual dashboards because Prometheus's built-in UI looks like a developer tool)
• *Alertmanager (handles the alert routing to Slack and PagerDuty when things break)
• *Node Exporter (to get basic server metrics like CPU and disk usage)
• *Kubernetes (has native service discovery so you don't manually configure 100 pod endpoints)
• *Thanos (for long-term storage since Prometheus deletes old data)
• *MySQL Exporter (to track database performance since Prometheus only handles HTTP endpoints)

The Catch

• !You're trading Datadog's $15-50/server monthly fee for 5-10 hours/week of your engineers' time
• !Local storage only keeps 2-15 days of data — anything older gets deleted unless you set up remote storage
• !High-cardinality labels (like tracking individual user IDs) will fill your disk in days and crash everything

Bottom Line

Free monitoring that actually works during outages, but you'll trade money for engineering time.