Star Trek has featured a plethora of great engineers over its long, storied history, including undersized Tellarites and science fiction's most famous Scotsman. A Starfleet vessel's Chief Engineer is usually its primary problem solver, figuring out how to make the impractical orders of their captains into reality. They also tend to be the primary outlet for technobabble, the partially fictitious technical jargon that is often utilized to explain away a problem with yet-to-be-created science and technology.
Nearly every iteration of Star Trek has featured either a Chief Engineer or an extremely similar position for its primary Federation ship or setting. The personality of Star Trek's engineers aren't exactly uniform, but they do tend to feature some similar traits, like the mercurial brilliance of Star Trek: The Original Series' Lieutenant Commander Montgomery Scott (James Doohan), or the charmingly nerdy enthusiasm of Lieutenant Commander Geordi La Forge (LeVar Burton) in Star Trek: The Next Generation. Whatever their personality quirks, a starship's chief engineer is an essential part of not only the ship's day-to-day operations but more often than not they're also a crucial member of the core cast.
