I don't know about Google, but where I work we have essentially one single technical line and people are expected to contribute to both development and making a

I don't know about Google, but where I work we have essentially one single technical line and people are expected to contribute to both development and making architectural decisions (and operations, etc, etc). Obviously, higher ranked staff are expected to make more architectural decisions vs. development, but it is a gradual growth process, and there are no positional distinctions.