How to organize the project structure for an application?

Proper organization of a Python project structure is the key to its scalability, ease of maintenance, and clarity for new developers. The first step is always a clear separation of domain logic and infrastructure code, such as working with databases or external APIs. Business logic must be clean and independent of external libraries or frameworks.

The second important principle is not to mix the API layer, for example, the FastAPI or Django web framework, with the internal application logic. If you decide to change the web framework or add a command-line interface, the domain code will remain completely unchanged. All dependencies must be strictly explicit so that modules do not circularly reference each other and clearly perform their tasks.

For organizing folders, it is recommended to use a standard and clear directory structure. Here are the main elements that should be laid down in the project from the very beginning:

By following these simple design rules, you will avoid the classic problem of monolithic spaghetti code. Over time, the project will grow linearly rather than exponentially complicate, which will save hundreds of hours of team work when adding new features.