Earlier quoted context omitted.
I love Dramatiq but I don’t get your point about task completion. You have to choose between at most and at least once.
The main problem with Celery is that it supports many brokers and many features. This creates many subtle edge cases, specifically for brokers not built with AMQP, for instance the "visibility_timeout" attribute of the redis broker which feels like a hack. This is why I created yet another task framework based on redis with robustness as a the main goal: https://github.com/NicolasLM/spinach
Fair enough but I always interpreted the Celery docs as saying Redis was kind of mostly unofficially supported as a broker.