We have a compute job scheduling system that often sees swings like that (bigger, actually!), where it goes from idle to having a ton of newly queued jobs ready

We have a compute job scheduling system that often sees swings like that (bigger, actually!), where it goes from idle to having a ton of newly queued jobs ready to run. But we use EC2 spot instances because they're much cheaper and the resource limits are much higher. It wouldn't matter if Fargate scaled out arbitrarily high, arbitrarily fast -- that's not really the problem with Fargate for our type of usage. We do orchestrate the EC2 spot instances ourselves, because ASGs and Spot Fleets are way too slow. Spot Fleet especially is like calling your grandma to have her click around in the AWS Console every time you want to scale. AWS is way too "polite" to their own infrastructure but when you do it yourself, you can slam right up against your rate limits.