The FirestoreIO connector (
BEAM-8376) for the Java SDK is currently out for review.
Some of the features for the Firestore connector are new relative to the Datastore connector, so the Firestore team would like to add them there as well. Most notably the Firestore connector has a gradual ramp-up feature that slowly increases throughput in line with Datastore/Firestore best practices.
Some minor adjustments to constants for batch sizing and backoff may also be worth looking at.