What is Cloud Pub/Sub? - ep. 2

This episode introduces Pub/Sub's topic-and-subscription model through the series' fictional order-processing system.

Key points

• Topics receive publications; subscriptions own delivery state: Publishers send messages to a named topic, while each subscription has its own backlog and acknowledgement path through push or pull ([00:00:00]-[00:02:06]).
• Separate subscriptions create fan-out: Two consumers that each need a copy use two subscriptions on the same topic; fan-in can route subscriptions from different topics toward one application ([00:01:03]-[00:02:06]).
• The example spans regions without defining every regional property: The fictional services use Pub/Sub as transport between US and European components, but the overview does not establish data-residency, failure-domain, or universal latency guarantees ([00:02:06]-[00:03:09]).
• Use cases span ingestion and asynchronous workflows: The episode connects event producers to processing, storage, notification, and serverless targets ([00:03:09]-[00:05:19]).

Current-use note: This is a 2019 conceptual overview. Recheck current endpoint requirements, regional behavior, product names, and delivery semantics before using its examples as architecture guidance.

Full video: https://www.youtube.com/watch?v=MjEam95VLiI(opens in a new tab)