Amazon Elastic Container Service can be configured with Auto Scaling by using the Target Tracking Policy

Service Auto Scaling can be set up by utilizing the Target Tracking Policy for the containerized services directly from the Amazon Elastic Container Service Console. With the Target Tracking, you can now choose a load metric for the service such as Request Count per Target and Average CPU utilization and then set the target value. Then the AutoScaling adjust the number of a task operating for the service to maintain the target value. Earlier you could only auto scale the Amazon Elastic Container Service utilizing the step scaling policies which will need you to build and manage Amazon CloudWatch Alarms for the metrics that you will want to trigger scaling adjustments.