Autoloading in Rails 7, get ready! | Riding Rails

The forthcoming Rails 7 represents a milestone for autoloading.There are two important changes coming:Zeitwerk has been the default autoloader for more than two years. Rails 6.0 and Rails 6.1 supported both zeitwerk and classic modes to help projects transition. This period ends with Rails 7: classic mode won’t be available anymore.Initializers can autoload reloadable constants if wrapped in to_prepare blocks, but they no longer can otherwise.Maybe your 6.x application is already ready for these changes. Otherwise, you can prepare in advance to ease the upgrade. Let’s briefly explore their implications.