[ElliotH]

At Google there’s not really such a thing as code that never changes. Your dependencies will shift beneath you, even if it’s just the compiler itself. More likely though the libraries you use have been updated, a robot or two have come through and applied automated fixes etc etc.

So if we’re using it once a year, (we do have tools like that, maybe not strictly annually but certainly rarely) then you do indeed want it to be automatically built on some kind of recurring basis so it’s ready to go when you need it. And the tooling makes it (relatively) easy to have that happen.