Heroku made their free tier awful. That's fair enough, but I need more stability.
So, I've spun up a Digital Ocean droplet and learned how to deploy Rails apps without the help of a PaaS.
It's not intuitive for someone who's used to provisioning PHP web app servers, but after finally getting it working, it's actually a pretty cool way of doing things.
So yeah. Obelisk, the Ruby on Rails blog engine I've written to replace the PHP-based Monkblog engine, is now running on a server that I've provisioned from scratch. Yay!