I think the key to getting a good answer here is the “beyond heroku” part. It is hard to make suggestions without knowing why a platform as a service no longer works.

There are so many different options available but they very for different needs.

Regardless, I would assume that you are going to have to pay more for a managed solution that managing everything yourself.

I know the founders at https://releasehub.com/ and it sounds like it might hit that sweet spot for “outgrowing heroku” but “don’t want to do full time devops”.