App service is alright but I'd recommend Heroku over app service any day. However, there is some visible work being done to improve app service like supporting docker compose files to run multiple containers but the basics are still very painful.

Most notably, swapping servers (slots) always caused downtime, accessing logs was flaky and slow, azure interface is just plain slow, continuous deploy was flaky (or it just didn't kick in until 20 min later?) and I had to manually restart servers many times