I've been doing Rails for about 12 years and at our shop we have it down. `cap production deploy` and it's done. Essentially zero downtime for deploys. Some

I've been doing Rails for about 12 years and at our shop we have it down. `cap production deploy` and it's done. Essentially zero downtime for deploys. Some things I'd note-- * Don't use puma or unicorn. Phusion Passenger and Apache is just fine performance-wise and is much more robust IMO. * To avoid ruby version conflicts use .ruby_version as your sole source of versioning. I use this in all my Gemfiles: `ruby File.read('.ruby-version').strip` * RVM isn't as popular as rbenv but it's amazing and you won't run into the issues you mentioned. It integrates with Capistrano and Passenger+Apache really well. * 2GB might be a bit light for a production app even with light load. We start our new VMs at 8GB and then adjust up or down as makes sense. We still do a single Ubuntu LTS VM for each app rather than anything fancy. Once you've added the stuff you need via apt it just works. Our sysops folks use Ansible playbooks that automate everything so there's no mystery when we need to do an OS upgrade or spin up a new VM.