It was my dream to go work at Google; after fighting the hiring system I was finally hired into Ads SRE and learned the infrastructure, parlaid that into a very nice role doing scientific computing using idle cycles, and even got to work with 3d printing and making and stuff (like Hixie, all thanks to Chris Dibona) as well as a number of state of the art machine learning systems. There really was an amazing feeling being surrounded by so many highly competent people (many of whom I see in this post's comments) who had similar vision to mine. But ultimately, so many things started to chip away at my enjoyment that I had to leave. Middle management was a big part of that.
Once you're on the outside, so many things that seem obvious (borg, beyondcorp, flume, google3, etc) aren't. It's almost like the future is here, it's not evenly distributed.