The Turkish scholar and engineer Al-Jazari died in 1206, but he left behind a fantastic legacy of devices, including a mechanical band and a mechanical waitress that actually served drinks.
While these inventions may seem trivial today, their contribution to engineering is indubitable due to their complex mechanisms and design concepts. Al-Jazari was the first to use crank shafts, cog wheels, delivery pipes, and one-way valves in pumps, among other innovations. Donald R. Hill, an English historian who specializes in Islamic mechanics, wrote in Studies in Medieval Islamic Technology that "the impact of al-Jazari's inventions is still felt in modern contemporary mechanical engineering."
Al-Jazari's most famous devices were clocks. They were beautiful sculptures that measured time by falling water, operated with gears and pulleys. They have not survived, but we have his original plans for them, illustrations, and reproductions, many of which you can see at Atlas Obscura.