Amazon RDS for PostgreSQL sudden drop in performance

What version of PostgreSQL? What instance type?
Have you tried Performance Insights?
https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_PerfInsights.html

Kyle

Hi,

Turns out our T2 instance had ran out of CPU credits, but this fact only became apparent after digging into CloudWatch metrics. It would be great if that info was displayed in the regular monitoring (as is the case for EC2 instances).