What it works really great for if you don't want to do the up front investment in managing a stateful cluster, is doing multi-step or fan-out processing. BEAM/OTP really shines when it's helpful to have individual processing steps coordinated but isolated, but where if a job needs to cancel and rerun (interrupted by a node restart or OOM), it's not an issue.
This is great resource https://www.erlang-in-anger.com/