Google Cloud Pub/Sub
Google Cloud's asynchronous and scalable messaging service that decouples message producers from consumers with typical latencies around 100 ms. Uses per-message leasing (not partitions) for parallel processing. Topics and subscriptions (push and pull), schemas (Avro and Protobuf), ordering keys, dead-letter topics, snapshots, and seek. Pub/Sub Lite offers a cheaper zonal/regional partitioned variant for high-volume workloads.