AWS CloudFormation change sets now support nested stacks

[AWS CloudFormation](/cloudformation/) is extending change sets to support applications modeled with nested stacks, enhancing the predictability of update operations. With this launch, you can now preview the changes to your application and infrastructure resources across the entire nested stack hierarchy and proceed with the update only when you confirm that all the changes are as intended. [Change sets](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/using-cfn-updating-stacks-changesets.html) offer a preview of how proposed changes to a stack might impact existing resources or create new ones. Nested stacks are stacks created as a part of other stacks, which allow you to model applications in a hierarchical way. For example, you might have security related resources in one nested stack and application resources such as databases in another. Partitioning applications this way improves code maintainability and facilitates reuse. Change sets support for nested stacks allows you to preview provisioning actions on resources, such as addition, modification, or deletion, across an entire application model so that you can make sure there are no unintended changes before you start an operation. When you create a change set with this feature enabled, CloudFormation automatically creates a change set for each nested stack contained in the hierarchy. Each of these change sets contains changes to the resources contained in the stack as well as links to change sets of stacks nested within it. Using these links for navigation, you can view the changes across the entire hierarchy. After examining all the changes, you can either choose to proceed with the create or update operation or start over. To get started, read the AWS CloudFormation documentation on using [change sets for nested stacks](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/change-sets-for-nested-stacks.html). Change sets support for nested stacks is available in all AWS regions that support CloudFormation, at no additional charge. For CloudFormation region availability, refer to the [AWS Region Table](/about-aws/global-infrastructure/regional-product-services/).