There probably isn't any one "platform/framework" they used. This beast touches too many systems, many of which are 'legacy' for the phrase "platform/framework"

There probably isn't any one "platform/framework" they used. This beast touches too many systems, many of which are 'legacy' for the phrase "platform/framework" to really apply. If it's anything like what I saw at the one (and only) government contractor I ever worked for, the site is a frankensteinian nightmare of COTS ('Commercial Off The Shelf') crap (which federal contracts encourage, when they don't outright require it) and sweatshop-style integration development run by contractors who hire anybody with a heartbeat and a handful of competent people, and pay them all peanuts while billing $200/hr in labor to the government.