Fargate definitely takes some time to figure out. It took a while for us to realize that we needed to bump up our instance sizes because the default instance was a t2.micro.

However, now that we got it configured properly (took about 6 hours over the span of 3 days to catch the issues), we flawlessly serve 11M API requests/day without a problem. We were running these on DO boxes, moved it over to elastic beanstalk which caused more problems than it was worth, and finally landed on Fargate.

Tried EKS, but it was a bit more cumbersome than we would have liked for a K8s service. (We run another product of similar scale on K8s via GKE).

If you're looking for something closer to Heroku than K8s, then Fargate is decent option.