We use RDS (with postgres), and puma workers. It's easy to setup nightly backups with RDS, and capistrano handles multiple machines.

I use Capistrano, which can do much of what ansible can, but more rails specific. It fetches the new source, compiles the assets, makes a git deploy tag, and restarts the servers etc. Deploying would look like this: cap production deploy or cap stage deploy It can do some basic things like restart puma servers as well