With a Kafka compatibility shim: https://github.com/googleapis/java-pubsublite-kafka
Disclaimer: I work for GCP.
https://cloud.google.com/pubsub/lite/docs https://github.com/googleapis/java-pubsublite-kafka
Disclaimer: I work on this product.
In the process of splitting up everything in modules.
( Microservices would be Overkill)