Google is a big enough organization that experience varies. When I was an SRE I wrote C++ code pretty much all day every day, even while being oncall, with only the occasional intervention necessary on my part. Teams like you describe are considered to be in "operational overload" and are actively dismantled by senior leadership, with responsibility for the dodgy systems devolving on the people who wrote them in the first place.
"Teams like you describe are considered to be in "operational overload" and are actively dismantled by senior leadership.."
-In theory, maybe... But with the expectation to stay in said team for atleast a year or two before switching teams and the associated difficulty in actually doing it, I think it is a pretty bad postion for said SREs to be in.
