My first ringworld!

[Suicide Junkie]

Yeah, fill 'er up with regular miners, and a robotoid fifth down the line before continuing to build miners (and the occasional farm and rad extractor)

Once you've got 99 facility slots filled, you can start building the monoliths to optimize production.
I'd reccommend having that starbase build a whole slew of spaceyard bases, and then have them all pump out platforms like there's no tomorrow.
Make satellites and fighters when the ringworld gets full