AWS has announced that you can use the Application Auto Scaling to add scaling to any services that is build on AWS Cloud

Application Auto Scaling enables its users to scale any services on the AWS Cloud so to automatically scale the compute and the data resources such as Amazon Elastic MapReduce, Amazon Elastic Container Service, Amazon SageMaker, Amazon DynamoDB, Amazon RDS Aurora Replicas, Amazon EC2 spot fleet or Amazon Appstream 2.0. The new custom Resource Scaling feature of the Application AutoScaling automatically scales any service that is built on AWS Cloud with adjustable resource capacity. You have to first register to an HTTP endpoint with the Application Auto Scaling Service to use the custom resource scaling which will use the endpoint to scale the resources.