3. Bookstack infra with Google auth, custom VPC 3. Bookstack infra with Google auth, custom VPC, RDS AutoBackup Off, Single-AZ, EC2.  ≈$84.25 The BookStack infrastructure is designed for a scalable and secure deployment . It utilizes a new VPC for network isolation, AWS Cognito for authentication , and RDS for database management in a Single - AZ configuration with AutoBackup disabled to optimize costs . An EC2 instance powers the application, while EFS Backup ensures data persistence. Secrets Manager and Systems Manager enhance configuration security, and CloudWatch Logs provide real-time monitoring and troubleshooting capabilities. You can always update the current stack using a Change Set to enable: • RDS Multi-AZ ( MultiAZ=true ) for high availability, • RDS AutoBackup ( AutoBackup=true ) for automatic backups, • RDS Deletion Protection ( DeletionProtection=true ) to prevent accidental deletion. However, you cannot switch from the default VPC to a custom one because the CIDR block differs , preventing the stack from being updated. For instructions on updating the stack using a  Change Set , please refer to the dedicated guide .