AWS has launched CloudFormation Express mode to accelerate infrastructure deployments by bypassing extended stabilization checks. According to AWS, this new mode reduces deployment times by up to four times for iterative development and AI-assisted workflows by completing the process once resource configurations are applied, rather than waiting for full resource stabilization.
How does CloudFormation Express mode speed up deployments?
CloudFormation Express mode changes when a deployment is marked as complete, not how the resources are actually provisioned. In standard deployment mode, AWS performs stabilization checks to confirm a resource is fully operational and ready to serve traffic before the process finishes.
Express mode skips these final checks. The deployment completes as soon as AWS confirms the resource configuration is applied. While the deployment is marked finished, the resources continue to become operational in the background. To prevent deployment failures caused by timing issues, CloudFormation automatically retries dependent resources that hit transient failures during provisioning within the same stack.
What are the performance gains for developers?
AWS benchmarking tests show significant time reductions for specific resource types. In one example, creating an Amazon Simple Queue Service (SQS) queue with a dead letter queue took 64 seconds in standard mode but completed in 10 seconds using Express mode.
The impact is more pronounced during resource deletion. AWS reports that deleting an AWS Lambda function with a network interface attachment can take between 20 and 30 minutes in standard mode; Express mode reduces this completion time to 10 seconds.
When should you use Express mode versus Standard mode?
The choice between modes depends on whether the workflow requires immediate confirmation that a resource is serving traffic.
| Feature | Express Mode | Standard Mode |
|---|---|---|
| Completion Trigger | Configuration application | Full stabilization check |
| Primary Use Case | Iterative dev, AI-assisted IaC | Production traffic shifts |
| Deployment Speed | Up to 4x faster | Baseline speed |
| Rollback Behavior | Disabled by default | Enabled by default |
AWS recommends Express mode for developers iterating on infrastructure configurations, testing individual application components, or using AI tools like Kiro that require sub-minute feedback loops. Standard mode remains the requirement for production scenarios where resources must be fully operational before shifting load or proceeding to the next stage of a pipeline.
How do you enable Express mode in AWS?
Express mode works with all existing CloudFormation templates, including nested stacks and change sets. When enabled on a parent stack, all nested stacks automatically adopt Express mode.
AWS Management Console: Select “Enable” under the Express mode option within the Stack deployment settings.
AWS CLI: Add the --deployment-config parameter set to EXPRESS when creating, updating, or deleting stacks. For example:
aws cloudformation create-stack
--stack-name my-app
--template-body file://template.yaml
--deployment-config '{"mode": "EXPRESS", "disableRollback": true}'AWS CDK: Use the cdk deploy --express command. This instructs the CDK to retrieve the generated template and deploy it via Express mode.
What are the risks and limitations of Express mode?
The primary trade-off for speed is the default disabling of automatic rollbacks. AWS disables rollback in Express mode to maximize iteration speed. For production environments, AWS advises setting disableRollback to false in the deployment configuration or implementing external monitoring and cleanup mechanisms to handle failed deployments.
AWS also notes that users should ensure IAM role templates continue to follow the principle of least privilege when building infrastructure incrementally.
Availability and Pricing
AWS CloudFormation Express mode is available in all AWS commercial regions. According to the announcement, the feature is provided at no additional cost. Users can track regional availability and future updates via the AWS Capabilities by Region page.