[Question from the form] Hardest thing you automated that looked simple

What was the hardest thing you automated that looked deceptively simple at first?

Apps that have a lack of documentation for their APIs can come back to haunt you.

Ultimately, something not documented at all or inaccurately documented can cause you to go down a rabbit hole of trial and error testing.

That can result in a lot of time wasted for something that once you figure it out would be considered a quick/easy fix.