Choose a Gateway Load Balancer (GLB) as the type of load balancer for the ECS service. Create a lifecycle hook to add new tasks to the target group from Amazon ECS as required to handle scaling. Specify the GLB in the service definition. Create a VPC peer for external AWS accounts. Update the route tables so that the AWS accounts can reach the GLB.

Choose an Application Load Balancer (ALB) as the type of load balancer for the ECS service. Create path-based routing rules to allow the application to target the containers that are registered in the target group. Specify the ALB in the service definition. Create a VPC peer for the external AWS accounts. Update the route tables so that the AWS accounts can reach the ALB.

Choose a Network Load Balancer (NLB) as the type of load balancer for the ECS service. Specify the NLB in the service definition. Create a VPC endpoint service for the NLB. Share the VPC endpoint service with other AWS accounts.