CASE STUDY / 01

When green health checks hid an outage.

I led investigation, recovery, preventive changes, and production release after stale database connections consumed Rails request capacity.

Production delivery

Rails / PostgreSQL · anonymized SaaS platform

Outcome Same monitored 504 pattern not observed for approximately one month.

The problem

Requests timed out while processes and PostgreSQL appeared healthy. Long-lived application-side connections could remain open while reads blocked, leaving request threads unavailable.

My decision & contribution

Restore service, then bound connection establishment and TCP failure detection. I verified applied settings, normal request behavior, and background jobs in staging, checked the production change, and added symptom-focused alerting.

What the result establishes

The same monitored timeout pattern was not observed for about a month. This is a bounded observation, not a measured availability percentage or a guarantee of zero incidents.