Well this explains why I was contacted twice. My expertise is in robotics and each time I asked them why they were interested, since I wasn't aware of much robotics work at Google (other than self-driving cars.) First time I asked the recruiter to email me so I could contact him at a more appropriate time -- I was at work -- and never hard from him. Second time was by email, and I responded but never got a reply. Oh well. I just don't understand why they would get my hopes up and then never respond -- anyone know how Google recruiters work?
Figured it was something like that. Was surprised to be contacted out of the blue, but I figured if I ever really wanted to work there I'd probably have to be the one doing the contacting.