Now a days, there are a lot of resources that explain how to program in a specific language or how to use a specific library or framework. But there is something more important than grasping a programming language or mastering a framework... being able to create software that it is easy to read, understand, change and scale over time. For me, this is the difference between a programmer and a Software Engineer. With this talk, I want to present the 5 SOLID principles that serves as a base to create software that is designed to persist in the time to have software systems that are easy to understand, test and change. All that with examples in Python.