The SOLID acronym is something we tend to hear a lot about in [Oriented Object Programming](Oriented%20Object%20Programming.md) (OOP). It's a mnemonic acronyme that list 5 design concepts intended to make software designs more understadable, flexible, maintainable and scalable. The 5 principles are : - Single-responsability principle - Open-closed principle - Liskov substitution principle - Interface segregation principle - Dependency inversion principle Going further : - [SOLID - Wikipedia](https://en.wikipedia.org/wiki/SOLID) - [SOLID & Ruby in 5 short examples](https://medium.com/rubycademy/solid-ruby-in-5-short-examples-353ea22f9b05) - [SOLID Design principle in Ruby](https://www.honeybadger.io/blog/ruby-solid-design-principles/)