Q objects enable complex query logic with OR, AND, and NOT operations. I combine them with | for OR and & for AND. The ~Q() syntax negates a condition. This is cleaner than raw SQL for dynamic filters. I build Q objects conditionally based on user

File uploads require careful validation for security. I validate file size using a custom validator and check content type. Using FileField or ImageField, Django handles storage automatically. I configure MEDIA_ROOT and MEDIA_URL for development. For

Abstract base classes let me define common fields and methods without creating database tables. I set abstract = True in Meta. Concrete models inheriting from the abstract class get all its fields and methods. This is perfect for timestamps, soft dele

Template tags extend Django's template language. I create simple tags with @register.simple_tag and inclusion tags with @register.inclusion_tag for rendering template snippets with context. Assignment tags store results in template variables. I place

Nested serializers display related data clearly but are read-only by default. To make them writable, I override create() and update() methods. For simple nesting, PrimaryKeyRelatedField or SlugRelatedField works well. For deeper nesting, I validate ne

Database transactions ensure data integrity when multiple operations must succeed or fail together. I use @transaction.atomic on views or functions to wrap them in a transaction. For partial rollbacks, I use transaction.atomic() as a context manager a

I use Django's cache framework to avoid expensive queries and computations. The cache_page decorator caches entire view responses by URL. For more control, I use the low-level cache API to store query results or computed values. I set reasonable timeo

Factory Boy eliminates boilerplate in tests by generating model instances with sensible defaults. I use Sequence for unique values, SubFactory for foreign keys, and post_generation for many-to-many relationships. The Faker integration provides realist

I use Celery for any operation that might be slow or fail intermittently, like sending emails. By decorating with @shared_task, I make tasks reusable across different apps. I set bind=True to access task instance (useful for retries), and configure re

I use PageNumberPagination for simple, bookmark-friendly pagination and CursorPagination when data changes frequently (prevents duplicate/missing items between pages). Creating a custom pagination class lets me control page_size, page_size_query_param

Custom managers encapsulate common query patterns. I create a manager method for each frequently-used filter like published() or active(). By returning self, I can chain manager methods. For more complex queries, I create a custom QuerySet class and u

I use clean_<fieldname>() to validate individual fields and clean() to validate field combinations. Raising ValidationError shows the message to the user near the appropriate field. For cross-field validation (like 'end date must be after start