Rock-SOLID Development Is Not a Fairy Tale

SOLID development - this means to write maintainable, flexible and scalable code.

I will explain the 5 ingredients to

- make your code easier to understand, modify, and extend
- make your code more robust and maintainable
- make your code less complex and less error-prone
- make your code more reusable

Transcript

1. Rock-SOLID Development is not a fairy tale Nicole Hummel, biz-design, TYPO3 Developer Days 2025
5. “everyone is so exhausted and tired”
6. “we have so much to do – each of us has many responsibilities and duties”
7. “use my Single Responsibility principle: everyone should focus on one task only”
9. “we need more houses but it takes too much time to build them”
10. “we need to tear down the old houses and start to build up the larger ones - it takes a lot of time, effort and resources”
11. “use my Open/Closed principle: use existing buildings and extend them to fit your needs”
13. “if our postman is sick, mail delivery is delayed by weeks”
14. “we are missing important news, because the mail is lost or arrives too late”
15. “use my Liskov Substitution principle: have multiple postmen with the same knowledge and workflow who can substitute each other”
17. “sometimes our bread tastes like sweet cake, and the baked goods are as hard as stone”
18. “we have one huge book with all the recipes – it’s hard to find the right one and remember each step”
19. “use my Interface Segregation principle: separate the recipe book into smaller ones, each dedicated to one section”
21. “repairs sometimes take a long time or cannot be done at all”
22. “our tools fit exactly into our toolboxes - if anything breaks, we need new tools and boxes and we have to adjust our way of working”
23. “use my Dependency Inversion principle: develop a toolbox that is universally compatible with all devices”
26. “my Single Responsibility principle: separate responsibilities into different classes, one responsibility per class”
27. “my Open/Closed principle: do not modify existing code; instead, extend it to add new functionality”
28. “my Liskov Substitution principle: subclasses should be able to replace their superclasses without causing errors or unexpected behavior”
29. “my Interface Segregation principle: create and use smaller, more specialized interfaces instead of a large one”
30. “my Dependency Inversion principle: prefer depending on interfaces and abstract classes rather than on concrete implementations”
31. QUESTIONS?
32. THANK YOU!
33. Photograph Credits All images in this presentation were generated using OpenAI's DALL·E 3, based on different custom prompts. Some of the images were color-adjusted in Affinity Photo 2.  https://chatgpt.com  https://openai.com/index/dall-e-3/  https://affinity.serif.com/en-us/photo/