My second job. I've been hired as a research specialist, not a developer, but they found out I could code during the interview.

Boss: hey, so we have our main product line that shares the control panel for all the models, right?
Me: unh, yeah
B: well, we need to know how it works.
M: sorry?
B: yeah, I mean, we should have a manual with all the tech documentation so we know how everything works
M: ...and didn't you handle the tech docs to the developers?
B: uh...no, actually we requests feature to the devs (note: external company) with a phone call, or email...now we need the specs.
Me: omg

...

The other company (which is part of the same group) handles me the source code.
It is a huge, 25k lines of spaghetti written by at least 7 people, one at a time, uncommented.
After a month I produce a 50page doc with how everything works, after actually compiling my resignation letter 3 times.

M: boss, here the docs
B: fine, I'll take a look
15 mins later
B: this is not what we need! You cannot describe those algorithm like this!
( I described the algorithms with their block flow, with a punctual verbal description)
M: umh.. So how do you need it?
B: we need an excel table, with all the entering conditions on the rows and all the exit conditions in columns, and the description of the condition of work in the crossing cells!
M: are you even serious?