Are you saying this from firsthand experience? Because it sounds like the sort of myth that Google would like you to believe. Much more believable is that their process is as broken and chaotic as most software projects are, they are just so big that they manage to have some successes regardless. Survivorship bias. A broken clock is still right twice a day.

That's my entire industry, so I can believe it. I'd love to learn large scale game architecture but it simply isn't public. At best you can dig into the source available 30 year legacy code of Unreal Engine as a base. But extracting architecture from the source is like looking at a building without a schematic.

Your best bet is a 500 dollar GDC vault that offers relative scraps of a schematic and making your own from those experiences.

I was an SRE on their Internet traffic team for three years, from 2020 til 2023. The move from Sisyphus to Legislator is something I wish the world could see documented in a museum, like the moving of the Cape Hatteras Lighthouse.