W.r.t. the PaaS platforms, I've had good experiences with Aiven's hosted PostgreSQL. It really is the turn-key solution I expected Heroku's Postgres to be (but which turned out to be confusing and you need to do manual work to upgrade etc.). https://aiven.io
I've heard good feedback from Aiven as well, but haven't used it. I know that there's ๐ people working there (Futurice alumni) ๐