Developers building Flask applications often encounter a frustrating circular import error. This occurs when two files try to import each other, creating a loop that Python cannot resolve. The classic example involves `app.py` importing `routes.py`, which in turn imports `app` and `db` from `app.py` before they are fully defined.

A proven solution is to move the import statement to the bottom of your `app.py` file. By placing `import routes` after initializing the Flask app, SQLAlchemy database, JWT manager, and Flask-Migrate, you guarantee these objects exist before the routes module tries to access them. This simple structural change resolves the dependency deadlock.

This pattern is standard practice in large Flask projects, especially when using extensions like Flask-SQLAlchemy. While it may seem counterintuitive, it ensures clean separation of concerns. For developers, mastering this technique prevents hours of debugging and leads to more maintainable code architecture. The next step is applying this principle across all modular components.