I've been using Celery on a small scale for years now and generally haven't had any serious issues except 1: reliably cancelling scheduled (future) tasks. Even using persistent revokes has been unreliable in my experience: https://docs.celeryproject.org/en/latest/userguide/workers.h...

Fwiw though, the alternatives (huey, dramatiq, rq) don't even seem to offer this feature.