Celery has always been a massive resource drain, and for pretty much zero gain. I'd suggest just saying "stay away from Celery" as it's easy to get going with, but really hard to scale or work with when you need what it promises. There are better options.
So far I've mostly used Celery in Python, but at jobs past there was also Sidekiq (granted, the use cases for that were a bit different, but it's kind of in the same bucket).
Haven't had the opportunity to work with them, but I've heard good things about SQS and other cloud queues, but I think those are fundamentally message queues, so you'd be responsible for writing a job queue layer over it, which can be a huge hassle.
