Celery Distributed Task Queue

Celery is a simple, flexible, and reliable distributed system to process vast amounts of messages while providing operations with the tools required to maintain such a system. It is a task queue implementation for Python web applications used to asynchronously execute work outside the HTTP request-response cycle. First released in 2009 by Ask Solem, Celery has become the de facto standard for asynchronous task processing in the Python ecosystem. The latest version 5.6.0 supports Python 3.9 through 3.14 and requires a message broker such as Redis or RabbitMQ for message transport. Celery provides a rich set of features including task retries with exponential backoff, task routing to different queues based on priority or worker type, scheduled tasks through Celery Beat for periodic execution, task chaining and grouping for complex workflows, task result tracking and storage through backends like Redis, database, or RPC, and remote control commands for runtime worker management. Celery integrates seamlessly with Django, Flask, FastAPI, and other Python web frameworks. Workers can be distributed across multiple machines for horizontal scaling, with built-in support for prefetch limits, soft and hard time limits, and rate limiting. The Flower monitoring tool provides real-time web dashboard for observing task progress, worker status, and queue metrics. Celery is used by Instagram, Mozilla, OpenAI, Reddit, and thousands of other companies for processing millions of tasks daily.