QoS Compatibility Is Part of the Interface

Matching topic names and message types are not enough if endpoint QoS policies are incompatible.

Treat QoS as runtime contract evidence, not decorative configuration.

Compare publisher and subscriber policies such as reliability, durability, history, and depth only where the lesson's supplied/runtime evidence exposes them.

Checkpoint

Given two endpoints, record the policies you can observe, identify one compatibility risk, and state whether communication is confirmed, plausible, or still unproven.

Do not infer successful delivery from configuration alone. Runtime observation remains the stronger claim.