One of the most popular "devops before devops was a thing" tools was Expect, which simulated an interactive session over Telnet or SSH. It effectively allowed ops to automate anything that could be done in a terminal.
Expect is a great tool and was widely used for such automation (including by EDA companies - along with Tcl), I've read. I tried it some and read the book about Expect by Don Libes, Expect's creator. A very good book, with a unique writing style, that I somewhat can't find words to describe well.
I'm obviously aware you can't be precisely specific, but I imagine that the level of detail you _can_ share is probably still very interesting.