One good use-case for still using queues is if your producer or consumer has spiky characteristics on small timescales, but predicatable perfomance if you zoom

One good use-case for still using queues is if your producer or consumer has spiky characteristics on small timescales, but predicatable perfomance if you zoom out enough. In that case your queue size spikes to some high value, but always returns to 0. The reasons for this can be numerous, maybe you produce a lot of jobs at once because of a user interaction, or your consumer is running slower for five minutes because some cron job is stealing your resources.