One of the first and most important requirements and security best practice to follow is to know about the AWS shared security responsibility model. Ensure that all stakeholders understand their share of security in AWS.
AWS is responsible for the security of cloud and underlying infrastructure that powers AWS cloud, and customers are responsible for security in the cloud, for anything they put in, and build on top of the AWS global infrastructure.
It is imperative to have clear guidelines about this shared security responsibility model in your organization. Identify resources that fall under your share of responsibilities, define activities that you need to perform, and publish a schedule of these activities to all stakeholders. The following figure shows the AWS shared security responsibility model:
Figure 1: AWS shared security responsibility model