"Cross-Cloud"
- AWS SQS → Google Pub/Sub：queue 模型搬到 topic + subscription 模型的跨雲遷移
SQS 是單一 region-scoped pull queue、Pub/Sub 是 global topic + first-class subscription 的 pub/sub 模型；這篇跨雲 migration playbook 走 6 維 diff dimension audit（components / data topology 軸 High）、對位 visibility timeout → ack deadline、maxReceiveCount → dead-letter topic、long polling → streaming pull、IAM policy → Service Account、SQS-to-many-consumer 要重設計成 topic fan-out；含 5 個 production 故障演練（fan-out 行為差 / ack deadline 太短重投 / ordering key vs FIFO / 跨雲網路成本 / DLT 設定差）跟 dual-publish 漸進 cutover