Cloud Run makes it possible to write functions that are not currently possible to do with Cloud Functions (e.g. when using software not included in Cloud Function system images). It also possible to register Cloud Run instances to direct eventarc events. Cloud Run instances can be run in local device as a docker instance.

Currently it is not possible to register locally running Cloud Run instance to triggers from local firebase emulator and there fore local development and testing is not possible for apps relying custom Cloud Run functions.