This is a development-only feature. Hanami uses Ruby gem to reload the code as-needed. New generated projects have this entry in their Gemfile:

Other Environments

Hanami doesn’t implement code reloading in its core.

Because shotgun is only enabled in development, all the other environments don’t have this code reloading feature. By excluding this feature from the core of the framework, we make sure that Hanami projects don’t mess with Ruby’s code loading mechanisms in production.