It is a managed Apache Beam service and is very useful for certain scenarios (like "hey, we have a million incoming PubSub messages that we need to transform into a dozen different branching streams of data"). It looks like even BigQuery actually transforms SQL statements into a bunch of Dataflow jobs.
But...
But...
- Minor version updates to Google Dataflow SDK once every couple of months while deprecating most other minor versions? Check.
- No visible contributions to Apache BEAM itself? Check. In 2021 I still don't know if I can use any Java versions beyond Java 8 to develop for and run in Dataflow. And Google is arguably one of the biggest users of Apache BEAm, and definitely a user with the largest pile of money to throw at the problem.
- They've recently sent out a questionnaire about Dataflow to some of their customers that feels like a "hey, we're definitely considering deprecating this, we're gauging the potential impact"