Stripe for payments, AWS Elastic Beanstalk for hosting/deployments. Wish there was an even dumber alternative to Beanstalk. I've been tempted to build my own thing to get closer to my ideal of uploading a jar and forgetting about it. (Raw javascript / vertx / postgres for actual development, but these aren't SaaS)
My experience with Beanstalk was much the same had the feeling of a lot of hacky Ruby, Python scripts thrown together. Logs in random place, sometimes would get "stuck"
Current project uses GCP App Engine "Flexible" which is easier and seems to be built on better foundations than Beanstalk. Build a docker image and run. Although like you we could skip the docker shenanigans and just need a JRE to run our uber .jar (distroless https://github.com/GoogleContainerTools/distroless/tree/mast... makes a basic JVM docker container easy)