You have to design and oversee the manufacturing of many products ranging from medical devices to new batteries.
You have to design power-producing machines such as electric generators, internal combustion engines, and steam and gas turbines as well as power-using machines, such as refrigeration and air-conditioning systems.
You have to design other machines inside buildings, such as elevators and escalators. You have to also design material-handling systems, such as conveyor systems and automated transfer stations.
You think water moves fast? You should see ice. It moves like it has a mind. Like it knows it killed the world once.