Solving Slow Load Time

It turns out the delay was being caused by config.assets.debug = true inside of development.rb. Setting this to false resolves the problem.

By default, caching is only enabled in your production environment. To play around with caching locally you'll want to enable caching in your local environment by setting config.action_controller.perform_caching to true in the relevant config/environments/*.rb file:

config.action_controller.perform_caching = true

Changing the value of config.action_controller.perform_caching will only have an effect on the caching provided by the Action Controller component. For instance, it will not impact low-level caching, that we address below.

More at http://guides.rubyonrails.org/caching_with_rails.html