I was very happy with fly.io - migrating my Rails app from Heroku was an absolute no brainer, took me like half an hour.
Then I tried Django, and all hell broke loose... Still some ways to go to catch up with Heroku on all fronts I suppose, but for Rails, clear recommendation.
I recently started the migration of my Django projects from Heroku to Fly. To test things out, I created this simple Django project. You might want to fork it and test whatever you need. I run into a few issues as well, all of them are described in the readme.
Sorry to hear Django was a pain. There’s a guide in the works for launching Django apps, but I can’t remember the exact status of that. https://community.fly.io/ is a good place to search for others who migrated or ask for help on there.
Then I tried Django, and all hell broke loose... Still some ways to go to catch up with Heroku on all fronts I suppose, but for Rails, clear recommendation.