Why are you running your own AMIs for ECS instead of just using Fargate?

The build pipeline I used in CodeBuild was build the Docker container and a sidecar Nginx container.

The parameter you pass in is the new Docker container you just built.

But how would LocalStack help?

You also don’t have massive CDK apps. The Docker images are going to change much more frequently than your persistent layer. You’re not going to be bringing up and down your VPCs, database clusters etc.

Own AMIs? Simply cost. No other reason, although we're evaluating it again, so we'll see.

We actually have several "massive" CDK projects now, depending on what metric you use for determining size. Our largest CDK app has more than 60 stacks, but with a cellular architecture that's artifially inflating the numbers a bit (n unique stacks against k AWS accounts where k > n but for n > 20, < 100) Maybe the speed at which we change persistent layers (99% additive) will slow down someday, but when you maintain a large number of services (>14) with constantly changing external contracts, it probably won't; it hasn't the last 6 years, it only gets faster.