Enhanced EventBridge custom event bus
One enhanced bus shared with RAM, a FIFO Subscriber that owns its filter, and ordered health alerts in another account — without bus-to-bus hops.
A classic custom bus in every account works until the next team needs the same stream. Then you stitch hops, stack charges, and bolt on a FIFO queue whenever order matters.
The enhanced bus flips that: lab owns one event-busv2, shares it with AWS RAM, and each consumer attaches a Subscriber. This lab proves the share, a DATA filter on source=iot.lab, FIFO delivery keyed by EventGroupId, and a short OPEN → CLEAR path into DynamoDB. Feed is an existing IoT talk stack via eb-bridge — the feature under test is the bus, not the devices.
AWS CLI only (eventsv2, ≥ 2.37.3), region ap-southeast-2, then tear down.