From the post:
Millennia of engineering has built the entire galactic civilization. Without it, beings would toil and strive on their native worlds, oblivious to all those oblivious to them in turn. And without their thousands upon thousands of Engineers, the Rebel Alliance would never be able to oppose the Galactic Empire’s brutal dominance. Engineers develop, build, and maintain every physical tool of the Alliance’s struggle, from the humble datapad to the impressive Home One.
Fully Operational, the next sourcebook arriving for Star Wars™: Age of Rebellion™, brings with it a host of new species, talent specializations, equipment, and game systems to help build out the critical role of the Engineer.