Well if only AWS provides the scaling you need then what would you migrate off of AWS to? You could re-arch your app to scale out for some use cases as you sugg

Well if only AWS provides the scaling you need then what would you migrate off of AWS to? You could re-arch your app to scale out for some use cases as you suggest, but that's also an indicator that using AWS allowed you to get to market faster with a much simpler system that didn't require a far more complex design, many more engineering hours and more admin.