Manage AWS IoT named shadows to represent independent subsystems of a single device

Steps

1. For each logical subsystem (e.g., motor, sensor, config), choose a distinct shadow name; use the named shadow MQTT topic prefix $aws/things/THING_NAME/shadow/name/SHADOW_NAME for all interactions.
2. Publish desired state updates by publishing JSON to the /update topic for that named shadow; the device receives the delta on the /update/delta topic containing only properties that differ from reported state.
3. The device applies the desired change, then publishes back to /update with a reported section reflecting the new actual state to clear the delta.
4. Use GetThingShadow via the REST API (GET /things/THING_NAME/shadow?name=SHADOW_NAME) or the MQTT /get topic to retrieve full shadow state from cloud services.
5. List all named shadows for a device with the ListNamedShadowsForThing API to enumerate subsystems without maintaining an external registry.
6. Classic (unnamed) shadows use the same topic structure without the /name/SHADOW_NAME segment; both types can coexist on the same thing.