What is the AWS CDK?

export class MyEcsConstructStack extends core.Stack {
  constructor(scope: core.App, id: string, props?: core.StackProps) {
    super(scope, id, props);

    const vpc = new ec2.Vpc(this, "MyVpc", {
      maxAzs: 3, // Default is all AZs in region
    });

    const cluster = new ecs.Cluster(this, "MyCluster", {
      vpc: vpc,
    });

    // Create a load-balanced Fargate service and make it public
    new ecs_patterns.ApplicationLoadBalancedFargateService(
      this,
      "MyFargateService",
      {
        cluster: cluster, // Required
        cpu: 512, // Default is 256
        desiredCount: 6, // Default is 1
        taskImageOptions: {
          image: ecs.ContainerImage.fromRegistry(
            "public.ecr.aws/ecs-sample-image/amazon-ecs-sample:latest"
          ),
        },
        memoryLimitMiB: 2048, // Default is 512
        publicLoadBalancer: true, // Default is false
      }
    );
  }
}

class MyEcsConstructStack extends core.Stack {
  constructor(scope, id, props) {
    super(scope, id, props);

    const vpc = new ec2.Vpc(this, "MyVpc", {
      maxAzs: 3 // Default is all AZs in region
    });

    const cluster = new ecs.Cluster(this, "MyCluster", {
      vpc: vpc
    });

    // Create a load-balanced Fargate service and make it public
    new ecs_patterns.ApplicationLoadBalancedFargateService(this, "MyFargateService", {
      cluster: cluster, // Required
      cpu: 512, // Default is 256
      desiredCount: 6, // Default is 1
      taskImageOptions: { image: ecs.ContainerImage.fromRegistry("amazon/amazon-ecs-sample") },
      memoryLimitMiB: 2048, // Default is 512
      publicLoadBalancer: true // Default is false
    });
  }
}

module.exports = { MyEcsConstructStack }

class MyEcsConstructStack(core.Stack):

    def __init__(self, scope: core.Construct, id: str, **kwargs) -> None:
        super().__init__(scope, id, **kwargs)

        vpc = ec2.Vpc(self, "MyVpc", max_azs=3)     # default is all AZs in region

        cluster = ecs.Cluster(self, "MyCluster", vpc=vpc)

        ecs_patterns.ApplicationLoadBalancedFargateService(self, "MyFargateService",
            cluster=cluster,            # Required
            cpu=512,                    # Default is 256
            desired_count=6,            # Default is 1
            task_image_options=ecs_patterns.ApplicationLoadBalancedTaskImageOptions(
                image=ecs.ContainerImage.from_registry("amazon/amazon-ecs-sample")),
            memory_limit_mib=2048,      # Default is 512
            public_load_balancer=True)  # Default is False

public class MyEcsConstructStack extends Stack {

    public MyEcsConstructStack(final Construct scope, final String id) {
        this(scope, id, null);
    }

    public MyEcsConstructStack(final Construct scope, final String id,
            StackProps props) {
        super(scope, id, props);

        Vpc vpc = Vpc.Builder.create(this, "MyVpc").maxAzs(3).build();

        Cluster cluster = Cluster.Builder.create(this, "MyCluster")
                .vpc(vpc).build();

        ApplicationLoadBalancedFargateService.Builder.create(this, "MyFargateService")
                .cluster(cluster)
                .cpu(512)
                .desiredCount(6)
                .taskImageOptions(
                       ApplicationLoadBalancedTaskImageOptions.builder()
                               .image(ContainerImage
                                       .fromRegistry("amazon/amazon-ecs-sample"))
                               .build()).memoryLimitMiB(2048)
                .publicLoadBalancer(true).build();
    }
}

public class MyEcsConstructStack : Stack
{
    public MyEcsConstructStack(Construct scope, string id, IStackProps props=null) : base(scope, id, props)
    {
        var vpc = new Vpc(this, "MyVpc", new VpcProps
        {
            MaxAzs = 3
        });

        var cluster = new Cluster(this, "MyCluster", new ClusterProps
        {
            Vpc = vpc
        });

        new ApplicationLoadBalancedFargateService(this, "MyFargateService", 
            new ApplicationLoadBalancedFargateServiceProps
        {
            Cluster = cluster,
            Cpu = 512,
            DesiredCount = 6,
            TaskImageOptions = new ApplicationLoadBalancedTaskImageOptions
            {
                Image = ContainerImage.FromRegistry("amazon/amazon-ecs-sample")
            },
            MemoryLimitMiB = 2048,
            PublicLoadBalancer = true,
        });
    }
}