In a post on the Dev.to site Dhurim Kelmendi shares an introduction to the SOLID principles of software development, a set of guidelines that can help to make your software more robust, flexible and testable in the long run.

This article aims to give a solid explanation of SOLID Principles and give some insight on their benefits and potential issues when applying them. Let’s go through each of them briefly.

He then goes through each of the principles and describes the basics behind them:

• Single Responsibility Principle
• Open-Closed Principle
• Liskov Substitution Principle
• Interface Segregation Principle
• Dependency Inversion Principle

The post isn't language specific so you won't find any code examples but it is a great introduction to the principles for those that are just starting out.