kaycey2022 parent
Is there any restriction on how many rails apps can be run on a 5$ digital ocean droplet?
Yes, memory. 4$ droplets have only 512mb. that's barely enough to run bundle install for one application.
6$ droplets give you 1GB and that's plenty for one app,
You might have some success if you run the build before deploying it (provided you use the same arch as the droplet). It's not going to give you a lot to work with and Puma's default config will take up most of it.
A 1/2GB box could run the bare minimum if you host the database on it as well. For a small scale app or a hobby/toy project that's going to do just fine.
You can run any number of them if you turn swap on. It will just be very slow.