The QuickSight Namespace CDK application is used to configure and deploy following resources:

QuickSight Namespace - Creates a QuickSight Namepsace via Custom Resource
QuickSight Namespace READER/AUTHOR Roles - Creates IAM roles suitable for federation into the Namespace as either an AUTHOR or a READER
QuickSight Namespace User Lambda and EventBridge Trigger - Watches for new users created using the Namespace AUTHOR or READER roles and automatically moves them into the namespace from the default namespace. Also, creates Quicksight Groups and moves the QS users into groups.