Multiple subscribers vs one consumer per message.
Pub/Sub vs Queues: multiple subscribers vs one consumer per message
absorb bursts before they become outages
Pub/sub is fire-and-forget; you need durability per subscriber.
Queues deliver each message to one consumer (work distribution). Pub/sub delivers each message to all subscribers (broadcast). Many brokers support both shapes; pick by what the workflow actually needs.
Queue: tasks that must be processed exactly once across workers.
Pub/sub: events that many systems should react to independently.
Combine: pub/sub topic with queue per subscriber → reliable fan-out.
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