If anyone is looking for a similar service to deploy Ruby/Rails apps, check out https://www.hatchbox.io from Chris Oliver. Unfortunately doesn't come with a free tier but worth every penny!
Caddy providers benefits compared to Nginx, like
- Out of the box SSL certificates
- REST api for providing configuration
- A vibrant plugin ecosystem to extend traditional web server functionality
- Easier setup for load balancer
We are quite happy with the results so far.