It looked as if it was made out of a shoe-horn, a metal pipe, and a coathanger. It was the simplest possible machine capable of firing repeating rounds.
the most basic model, the Mark III, could be produced from five man-hours work. Some of the cheapest versions were made from only 47 different parts. It was distinctive for its bare appearance (just a pipe with a metal loop for a stock), and its horizontal magazine.
The Sten was not designed by an accountant, manager, MBA or anyone on the leadership track at a large corporation. It was designed by two guys whose job it was to build stuff.
Now it wasn't an ideal weapon - it misfired, it jammed, it roasted eggs, it sometimes fired off an entire cartridge at once - but this was wartime, and Occupational Health and Safety wasn't a big thing back then. England had no machine guns and no stuff with which to make them.
So Shepherd & Turpin got asked "make us the cheapest simplest possible machine gun that will kill people. Or else we all die at the hands of the Nazis." They slapped something together based on that specific scope of work.
A fucking accountant or MBA wouldn't know where to start. They would have held fucking focus groups.
Remember this next time someone yaps about cost control in the miners: it's not the stuffed suits or the pencil-pushers who know how to get a job done cheap. If you want someone to strip down a project to its bare essentials, and quite possibly save yourself 20-80% in costs, you go to the engineering and construction staff.
The guy with the shovel knows how to dig a fucking hole.
PS in case you think I'm being an Anglophile, the whole Sten bit could just as easily have been written about Stalin's Katyusha rocket launchers - which were basically Studebaker pick-up trucks with rockets on them.