What did people use to spin up servers quickly before modern DevOps?

It is relatively recent (20 years) that an individual developer could control the machine they work on; and that 'production' machines have hundreds of dependencies installed to support "your app".

Until those numbers exploded, a script, a list of instructions, or something like kickstart worked fine.

We have traded the complexity of writing code, for the complexity of managing how others code is installed and configured.

A good trade off? Probably in aggregate, but not in the extreme (looking at you, node-js).

Kickstart: https://en.wikipedia.org/wiki/Kickstart_(Linux)

thanks i didn't know about that

No, servers came with PERL and/or PHP, no config necessary.

Machine images, centralised software deployment.

whats that