The Economics of Self-Hosting vs. Managed Monitoring
The "Obvious" Math That's Wrong Engineer A: "Datadog is $15K/month. Prometheus is free. We should self-host." Engineer B: "But we'd need to pay an SRE to run it. That's $150K/year." Engineer A: "Prometheus doesn't need a full SRE. It's easy." Engineer B: "Famous last words." This conversation happens at every company. Both sides have points. The real math is more complex. The Total Cost Breakdown Managed (Datadog, New Relic, Dynatrace) : Licensing: $X/month (scales with hosts, events, logs) Integration time: 1-2 weeks per service Training: 1 day per new hire Ongoing: minimal Self-hosted (Prometheus + Grafana + Loki + Alertmanager) : Infrastructure: hosting costs (~$500-$5000/month depending on scale) Initial setup: 2-4 weeks of engineering time Ongoing maintenance: 10-20% of 1 FTE Upgrade costs: quarterly, each upgrade ~1 week Storage growth: ~20% per year Expertise: junior → senior SRE hire required The honest answer: managed is cheaper for teams under 50 engineers. Self-hosted becomes cheaper around 200+ engineers if you can run it well . The Real Variables It's not just licensing cost vs. hosting cost. These factors matter more: 1. Data volume growth Managed tools charge per GB ingested or per metric. If your logs 10x, your bill 10x's. Self-hosted scales linearly with compute. You control the growth. 2. Retention requirements Managed tools often charge extra for long retention. Self-hosted you store as much as your disk allows. 3. Cardinality Prometheus dies at high cardinality. Datadog handles it but charges more. High-cardinality metrics are where self-hosted breaks. 4. Incident rate Heavy incident load means heavy query load on your monitoring tools. Self-hosted needs bigger compute for this. 5. Team expertise If your team has never run Prometheus, you'll spend 6 months in the pit learning cardinality mistakes, retention tuning, and HA setups. That's not free. The Break-Even Calculation Rough calculation for a 50-engineer startup: Managed (Datadog) : - Licensi