I’m often taken aback by the number of mistakes IT made with on-premises traditional systems that it’s now replicating in the cloud. If you have a cruddy applications design or overall architecture and relocate it the cloud, you end up with cruddy IT assets that are now in the cloud.
Fact: The cloud is not an automated change agent for bad IT decisions. Indeed, those bad decisions will typically be amplified in the cloud because you can move faster and so encounter mistakes much sooner—and perhaps more often.
The biggest architectural mistake that I see in the cloud involves coupling. Back in the day, applications were tightly coupled between other applications and data sources. If one thing stopped, the entire system stopped. So if the database went down, all connected applications did as well, including any systems that sent or received data from the database.