I know someone who was hired (around turn of the century) because they knew how to xml with a certain kind of then-important big systems api
the stories I’ve heard from there are hilarious
but is also incredibly ease to create proprietary semantics with
christ the shit I’ve seen with network vendors…. shibboleth NETCONF/YANG. advance warning; abyss grade 6+
And yet there are some tasks I wish I could do in NETCONF instead of the thing we’re actually using, but apparently the documentation for this interface is difficult and expensive for the company to get my hands on, for reasons.