Celery Patterns for Django

Core Philosophy

• Idempotent tasks: Running a task twice must produce the same result
• Pass IDs, not objects: Arguments must be JSON-serializable
• Always handle failures: Log errors, never swallow exceptions silently
• Proper retry strategies: Use exponential backoff for external services

Task Design

Structure

• Place tasks in apps/<app>/tasks.py
• Use @shared_task for reusable tasks across projects
• Use bind=True when needing access to task instance (retries, task ID, state updates)
• Add type hints to task signatures
• Log task start, completion, and failures