What sort of workflows do you run in Apache Airflow? Are they automating interactions with partners/clients or internal communications? How can it become so sca

What sort of workflows do you run in Apache Airflow? Are they automating interactions with partners/clients or internal communications? How can it become so scaled up that they (and many people in the comments here as well) have trouble managing the hardware? How can it become so complex that the workflows need to be expressed in DAG's? What's a workflow? I don't think I ever worked anywhere that had automated workflows, though my I only worked for small startups so far.