Sorry, but I haven't seen his code base, and I don't know any significant technical achievement of his other than spamming everybody with Chrome download links everywhere to make it the number 1 browser (it was a great strategy, but not enough to run a company).
Google is paying Jeff Dean, the guy who even after was famous for a lot of things, after imagenet challenge result came out, stopped everything else, read research papers for a week, and implemented a system that separates dogs from cats with unprecedented precision.
People like Jeff Dean or Demis Hassabis are the kind of people who can make me stop everything I'm doing and listen to them when they say that the company should go into a direction.