Interesting. At first I was thinking this might be part of their cross-platform (iOS&#x2F;Android&#x2F;web) architecture that they use for Inbox, Sheets, and a few other things.<p>E.g. they assert that, despite having pure-native views (e.g. no Swing-style &quot;one UI for all platforms&quot;), they share ~70% of the client-side code across iOS&#x2F;Android&#x2F;web.<p>Which to me insinuates the reused code is probably things like the domain models, validation rules, and also online&#x2F;offline data storage&#x2F;sync logic.<p>E.g. maybe Lovefield was part of that cross-platform client-side storage architecture. But probably not since it&#x27;s Javascript. (Which is fine, Google is a big place&#x2F;lots of different apps&#x2F;needs.)