I'd guess that there isn't one single person at google who knows all of it. They do base a lot of their stuff on LSA (I think probably more generally just NLP)

I'd guess that there isn't one single person at google who knows all of it. They do base a lot of their stuff on LSA (I think probably more generally just NLP), but they have so many filters and minor adjustments that the whole thing is like a really complex ball of string. I doubt there's one person who knows how the whole thing is exactly put together.