django-patterns

Use a config package with split settings files (base.py, development.py, production.py, test.py) and place apps in a dedicated apps/ directory. Each app should contain models, views, serializers, services, permissions, and filters modules for clear separation of concerns.

Use select_related for foreign key relationships and prefetch_related for many-to-many relationships when querying. Define custom QuerySet methods like with_category() that encapsulate these optimizations so they are applied consistently across the codebase.

The service layer pattern moves business logic out of views and models into dedicated service classes in a services.py module. For example, an OrderService handles order creation, payment processing, and email notifications using transaction.atomic for data integrity.

Yes, use the @action decorator to add custom endpoints to ViewSets, such as a purchase action on a product or a featured list endpoint. You can specify detail=True for single-object actions and override permission_classes per action.

Use signals like post_save for cross-app side effects such as creating a user profile, keeping apps decoupled. Override save() for logic intrinsic to the model itself, like auto-generating a slug from the name field.

Use Django's low-level cache API with cache.get and cache.set to store query results with a timeout, checking the cache before hitting the database. For simpler cases, apply cache_page decorators to views or cache template fragments with the cache template tag.