A company is building an on-demand video service using microservices. The service will launch with 5 million users and grow to 30 million users after 6 months. The application is deployed on Amazon ECS using AWS Fargate. ECS services communicate over HTTPS. A solutions architect must implement blue/green deployments, route traffic to each ECS service through a load balancer, and ensure the application automatically scales the number of tasks in response to an Amazon CloudWatch alarm. Which design meets these requirements?

The correct option leverages AWS Fargate's native capabilities. Blue/green deployments are directly supported in ECS, and an Application Load Balancer (ALB) is ideal for HTTP/HTTPS traffic, offering advanced routing features necessary for microservices. Service Auto Scaling for ECS services automatically adjusts the number of Fargate tasks based on CloudWatch alarms, effectively handling the projected user growth without manual intervention. Incorrect options: Using a Network Load Balancer (NLB) is less suitable for HTTPS microservices as ALBs provide more advanced routing and HTTP-specific features. Requesting quota increases is a manual process and does not provide automatic scaling. Cluster Autoscaler is typically used with EC2 instances in an ECS cluster, not with Fargate, which is serverless. Similar to the previous point, using Cluster Autoscaler with Fargate is incorrect. While an ALB is appropriate, the scaling mechanism is not.