I agree that the Heroku developer experience has been second to none. I'm a front-end & DX engineer at Northflank and we're working hard to evolve and create a next-gen iteration of the Heroku experience anchored around 12 Factor Applications in a Kubernetes/cloud native era. We're getting very close, come and see for yourself:
https://northflank.com. Some key features:
* As simple as `git push` to build & deploy services
* One-click addons for Postgres, Mongo, Redis, MySQL and more
* A generous free tier to get developers on board with minimal friction
* Great out of the box observability
* The option to set up pipelines for more complex build/preview/release workflows