I recently implemented Capistrano for the first time with a new cloud production environment. When I run cap deploy, everything seems to work fine. I can visit my live application in the browser, but my static files seem to load very slowly (like 5.0-12.0s).
See answer for clarity on config.assets.compile.
Static files load slowly because they possibly are not static, but are being served by Sprockets.
Check in production.rb and see if config.assets.compile = true or it is not set. That would mean that Sprockets is doing the work. You would also see far-future headers being used.
Have a look in /home/my_user/my_app/current/public and see if assets exists; I suspect it does not.
That means that mkdir -p is not working. The most likely cause is that the deploy user does not have sufficient permissions to create the directory.
Fix that, and also check (if this is an upgraded app from 3.0 or before) that your config setting match those in the last section of the pipeline guide.