Interesting. At first I was thinking this might be part of their cross-platform (iOS/Android/web) architecture that they use for Inbox, Sheets, and a few other

Interesting. At first I was thinking this might be part of their cross-platform (iOS/Android/web) architecture that they use for Inbox, Sheets, and a few other things. E.g. they assert that, despite having pure-native views (e.g. no Swing-style "one UI for all platforms"), they share ~70% of the client-side code across iOS/Android/web. Which to me insinuates the reused code is probably things like the domain models, validation rules, and also online/offline data storage/sync logic. E.g. maybe Lovefield was part of that cross-platform client-side storage architecture. But probably not since it's Javascript. (Which is fine, Google is a big place/lots of different apps/needs.)