For broad-spectrum roles like software engineers, Google hires people first and then figures out what team they should join later. If you want a specialist role, then you'll need to find one on their jobs page.

To illustrate, here's the kind of thing Mr. TCP kernel module should be applying for: https://www.google.com/about/careers/search#!t=jo&jid=107205...

And here's the kind of generic role they probably shouldn't be: https://www.google.com/about/careers/search#!t=jo&jid=34154&