A mixin in Ruby is a way to include reusable modules into classes without using traditional inheritance. Instead of extending a single parent class, you can mix in shared behavior across multiple classes using Ruby modules. This makes your code more modular, flexible, and easier to maintain.

Mixins are especially useful when you want to share functionality across unrelated classes, avoid code duplication, and keep your application clean and scalable. For example, you might create a module for logging, authentication, or payment handling and then mix it into different classes as needed.

👉 To dive deeper into how Ruby modules and mixins work, check out this detailed guide: Ruby Module