Things to think about relative to code design. This is where the rubber meets the road and all of your previous work really starts to pay off, since you can now interact with your wonderful system and all of the beautiful data you've architected. I discuss code layers, and show an example app I worked on recently to illustrate ways to organize your folders and files according to your code layers.
For more information on code design patterns:
https://en.wikipedia.org/wiki/Softwar...
https://refactoring.guru/design-patte...
For more on clean code and code craftsmanship:
https://www.amazon.com/s?k=clean+code...
• Clean Code - Uncle Bob / Lesson 1