Fast adhoc aggregations over firestore isn't a reasonable possibility. A graphql api or not doesn't really matter since that's just an abstraction for querying

Fast adhoc aggregations over firestore isn't a reasonable possibility. A graphql api or not doesn't really matter since that's just an abstraction for querying a service or database. I really mean something like an open source Amplitude or Keen where you can dump events into it and then aggregate/group them in any way you like on demand.