They started on their drone journey buying cool consumer drones on aliexpress for $100 or so and modifying. They have access to the internet and enthusiast blogs and have rapidly grown their industry. Obviously unlike quadcopters they don't rely on wifi but rather use other RF bands. These people have lived there in the desert for tens of thousands of years. They are smart people and able to understand and improve on designs.

It's not particularly sophisticated, liek on the Manhattan Project level requiring state backing. There are kids doing this stuff for fun without their parents even realizing.