Running Celery + Redis in production is easy — until it isn’t. What works locally quickly breaks under real load: tasks pile up, workers crash, and retries cause cascading issues. These problems are particularly common when using Redis as a broker. RabbitMQ provides stronger delivery guarantees out of the box — durable queues, acknowledgments, and better failure handling — while Redis requires more careful tuning to avoid task loss and inconsistent behavior. Celery out of the box is not the same as a production-ready system. Reliability requires careful configuration, proper queue design, and solid observability. In this guide, I’ll walk through what actually matters to make this stack stable and predictable in production. Visibility timeout Let’s begin with a very confusing but important configuration for applications that use Redis or SQS as message brokers.…