- Symptoms of bugs are treated, not the root cause. This one varies but there is a consistent lack of analysis in understanding the problem.
- Architectural mistakes re-occur, but not their solutions. Problems that aren’t/weren’t well understood from past architectures/implementations crop back up.
- There is a superficial understanding of the problem that leads architects/managers at the top to make decisions out of fear: "Feature X used EC2 instances. EC2 instances are REALLY expensive. Therefore we shouldn’t use EC2 instances ever." The real problem is not EC2, it is how our company migrated a monolithic application without refactoring with the new environment in mind.