When most people look at migrating to the cloud, they're primarily concerned with cost and performance. As much as we'd all like to be able to focus on critically important aspects of cloud computing such as security, availability, and data governance, the questions of how much it costs to run and whether it can keep up with the workload and provide the right features often steal the spotlight.
It's not hard to see why this is the case. Cost and performance are constants that, if out of line with expectations, become problems immediately, whereas considerations like security and availability rise to the top of the pile only when something goes wrong. It's also not always clear to cloud users that some aspects of operating in the cloud are still their responsibility rather than the service provider's.
The easiest way to avoid this trap and make sure that all aspects of the infrastructure are carefully considered is to visualize the cloud infrastructure as you would your on-premises infrastructure. Yes, the cloud is a fundamentally different beast than a traditional infrastructure, but it is also similar in many ways. Although it's true that the cloud service providers you've opted to use may perform many tasks you would have done on premises, you still need to know how they're doing it and make sure your -- and your stakeholders' -- expectations are adjusted appropriately.