She was very successful at Google. Her taste drove much of Google's early design aesthetic. Why is the landing page mostly blank? In large part because Marissa insisted.
"There will be no banner ads on the Google homepage or web search results pages. There will not be crazy, flashy, graphical doodads flying and popping up all over the Google site. Ever."
She said that in 2005. And a clean design was quite revolutionary at the time--yahoo and all the other internet portals were cluttered and sticky.
She isn't solely responsible for this aesthetic of course, but it really was her driving much of the theory.
See also, eg, https://daringfireball.net/2008/03/kahney_jackass (the original citation has fallen off the net, unfortunately) where Marissa is cited as being the driving force behind most product look and feel.