The modern tactical landscape favours what I've been calling "tactical diversity". Here's a nice piece about the idea from Jacob. I can't imagine the abuse I'd get from Joe Devine if I'd referred to it as "polyvalence", though...
Shell scripting is the one skill that separates DevOps engineers who panic during incidents from those who fix them in minutes.
I spent 8 years in Linux before I got into DevOps.
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