Take an F-15 Eagle. Keep the FAST packs from the Strike Eagle, upgrade the avionics and engines.
Fit 12 to 20 of the latest AIM-120 and AIM-9 missiles.
Create air combat doctrine to perform the "Itano Circus", "Macross Missle Massacre", or "Roboteching" on enemy aircraft.
Write internet jokes at Russia's and China's expense.
Does that answer your question?
Yeah, but they should have come up with a better name than F-15EX which takes very little to look like F-1SEX.