Think of it the other way round - if your workload is not realtime, but "within minutes/hours", as in processing feeds here - scaling the worker nodes with an a

Think of it the other way round - if your workload is not realtime, but "within minutes/hours", as in processing feeds here - scaling the worker nodes with an ansible scripts needs to be done on maybe a weekly (if not monthly or less) basis and you get 4/3 instead of 3/3 - for a few minutes of work. This just does not seem to be the workload for autoscaling and adding complexity. I've ran a similar setup at a past job - we planned for whatever but in the end it was one person clicking a few buttons to provision a new instance once in a while. Also some workloads are really bad for lambda, because you can (total napkin math) run 4 cores at 100% load for 24h a day to do your processing, all at the cost of "1 instance".