Cafeteria IT
I was requested to design a setup for a buffet style restaurant. Cameras, wifi, doors, internal data. Easy enough, POE cameras, door actuators and WiFi hotspots, cabling above the false ceiling, VPN programmed switch and UPS in the manager's office. They picked a reputable firm to do the installation and I went on to other things.
A few months later, I was yanked off another job to the scream of an impending lawsuit to find out why this setup was no longer working. A few minutes after getting there, it was obvious why the system no longer worked. The manager had decided that the wall rack should not go in his office, and instead had them put it in the back room. That room had their deep sink, cleaning gear, chemical storage and the very large hot water heater, and it had no ventilation. Every bit of exposed copper in the patch panel was green, the UPS had shorted out when it was doused with fluid of some kind, and I still don't know how the switch survived.
I took pictures and told the business to pound sand, they would get laughed out of court if they sued. After I was reprimanded for harsh language and folks had some time to cool down, I was asked how what they had could be made to work for the least amount of additional money. Since the cabling as built wouldn't go to the manager's office, I stuck the rack above the back room, and rigged up some ventilation for it. We cut a few feet off each wire, patched it into a new patch panel, replaced the UPS and it was good to go. The only problem was that you needed an eight foot ladder to get to it.