There are a few inaccuracies here about the Google SOA, eg. there are language restrictions at Google and they meant to say GFS instead of Colossus in several places (Colossus has a different architecture that isn't exactly what I'd call "cleanly layered".)
Their overall point about the system having evolved organically rather than being designed by a single architect stands, though.
Their overall point about the system having evolved organically rather than being designed by a single architect stands, though.