As a software lead and feature developer, I witnessed a team learn an important lesson about resource scaling and the cloud. Spoiler alert: the lesson was that if you’re not careful, scaling can get expensive!
The team felt they had no choice but to keep increasing the number of instances for a given service that was under heavy load. When they finished scaling up, the number of instances was several times larger than the number of instances that were configured by default. What they didn’t realize at the time was that—despite the load returning back to a normal state—their extra instances remained in place.