I loved when dependencies were manual jobs on local machines that some recently fired dev had been running for 3 years but IT had already wiped their machine.
Deserved to be fired for that one but man did it suck to deal with.
One had a crappy backup policy, I replicated the prod database to my workstation and took snapshots twice a day. That saved us TWICE!
The other time and I believe I still have an account running in their systems, they wanted to force devs to use Python 2.4 because that is what was in the base system included. I built my own Python plus deps and rsynced it to all the prod machines.
When I left and they disabled my account they enabled it a couple hours later. It was reportedly still running years later.
Deserved to be fired for that one but man did it suck to deal with.