Monitoring Multiple Domains at Scale in 2025
When you manage 5 domains, manual checks are fine. At 500+, you need systems. Here’s how large teams do it.
Centralized Inventory First
Every mature team starts with a single source of truth — a CSV, database, or DNS zone export listing all domains and their certificate sources.
Automated Daily Scans
- crl.sh + ctsearch — free Certificate Transparency monitoring
- SSL Labs API — deep certificate analysis
- Custom scripts using AxelBase logic
Alerting That Actually Works
Send alerts at 60, 30, 14, 7, 3, and 1 day before expiry — to Slack, email, and PagerDuty.
Integration with CI/CD
Block deployments if staging certificates are near expiry. Fail fast, fix early.
Pro Move: One Fortune 500 company runs 17,000+ certs with zero manual renewals using full ACME automation.
Tools That Scale
Start simple with AxelBase SSL Checker for spot checks. Graduate to CertSpotter, Keychest, or AWS Certificate Manager for enterprise scale.
Never be the person who takes down production at 3 AM.
Scale doesn’t have to mean complexity.