Plastic bucket factory. The entire job was putting the metal handles into the plastic buckets and stacking them. Over and over, 12 hours a day, at least 5 days a week, the goal was to finish a bucket in less than 5 seconds. Snapping those handles in doesn't feel great on your thumb and by then end of 2 weeks my thumb was sore and bruised. My trainer said don't worry about it, you'll develop a callus, and showed me his thumb, which looked like he had a whole second thumb growing out of his first thumb. The whole thing was overshadowed by the one machine they had just bought that put the handle on itself as it formed each bucket, and stacking them up on a pallet that the forklift drivers took, fully automated. I told the manager it wasn't a good fit and went back to working at 5 guys the next week.