Aerospace vehicles are designed in a hierarchy with a whole lot of individuals specializing in one piece of one subsystem, but by the nature of aircraft everything is very codependent.  You can&#x27;t just design thermo, avionics, structures, aero, payload, etc. in a vacuum; the tiniest details of one subsystem have reverberating effects in all of the others.<p>At the top you usually have a set of old guys (you might have read Skunk Works, those old guys are Kelly Johnson and Ben Rich in that book) but in this case Musk and likely a few others... a set of people who have to know a little bit about everything and enough to drive the important piece of engineering of the moment towards a successful project.