Separation of Concerns
Domain: Design Principles
🎯 Motivation
Split a program into sections where each addresses a separate concern. Mixing UI, business logic, and database access in one place makes every change risky and testing difficult.
📋 Concrete Example
A web app separates routes.py (handling HTTP), services.py (business rules), and models.py (database). Each layer can be tested and updated without affecting the others.
🔗 Analogy
A newspaper separates news, opinion, sports, and ads into different sections. If ads appeared inside news articles, readers would distrust the reporting and navigation would be chaos.