It started with a seed of an idea, in my case specifically "what if the tech billionaire ruling class actually got everything they said they wanted, including offworld fiefdoms, clinical immortality, and no restrictions on their power or inhibitions on their whims," extrapolated on what that would look like, added in the limitations of material reality (such as how ruinously costly it would be to supply an unsustainable Martian fiefdom with a poisoned a depleted Earth's resources), weighed in the class struggles of the precariat left behind on the plundered and slowly-being-killed home planet, and then I added mechas because I love mechas.