For over ten years.

They're also the world's largest computer manufacturer (for internal data center hardware).

Software people tend to think chips and hardware design are magic skills known by only three revered people in the world. It's just another track of school you could have chosen. ("Google writes its own software now?")

I think I recall them making custom 10gbit Ethernet switch fabrics.

They used merchant silicon in their custom switches. Modern switch ASICs are 2+ billion transistor devices with lots of fancy custom logic for SRAMs and TCAMs and analog magic for PHYs. Even Google can't afford to do that by itself.

Pfft. They can just map-reduce over each bit in the frame.