I used to work for a large, old company whose products you have all bought and buy (and which shall remain nameless) about 15 years ago. I worked on data interchange between the systems used for record keeping of said products and various other downstream or parallel systems (same purpose, separate system because left over from merger/acquisition).
So basically bulk data import and export. The product was 15 years old at that point. Data interchange was via various fixed width or delimited (CSV but the C might be some other character or character sequence) files transferred to and from various SFTP servers.
It's been a while but there were probably like 20 or 30 different such data sources or exports going in and out. Worked like a charm. I bet they're still used without much change. The frontend was being rewritten at the time (old one was in Smalltalk).