It's pretty subjective, but we tried moving our task-driven frontend
load to dynamic backend instances. We found that, perhaps due to the
nature of our workload, the dynamic backend pools never shrunk - e.g.,
if I configured 5 instances, 5 were always active. This had the effect
of costing a lot
With backend instances, the full scheduling control can be achieved by
using pull queues. So you could design your system to enqueue deferable
latency-tolerant tasks to a pull queue. When front end instance determines
that enough tasks have been queued up in the pull queue, it sends a
trigger
