Comment by shadowgovt

The company is big enough for both of them to be correct.

I have firsthand knowledge that Cloud, for instance, did not test regularly directly on Firefox. Team couldn't justify the cost of setting up and maintaining a FF test suite to satisfy 1 in 50 users, so they didn't (and nobody up-chain pushed back on that). Testing was done regularly on Chrome, Safari, and Edge, as per the usercounts and "top three browser" guidance (at the time, we didn't even test regularly on mobile, since there was a separate mobile client).

But the analytics team? I'm sure they test directly on Firefox. They're just testing an entirely different piece of the elephant and their end-to-ends won't include how, for example, changes they make interoperate with Firefox in the context of Cloud. Or YouTube. Or etc. Not unless they have a specific reason to be concerned enough to.

Google's like any other megacorp in the sense that costs of cross-team coordination are combinatoric.