If the inventory manager is down, no updates to the stock can occur, so what notifications are there to be sent? You can&#x27;t eliminate coupling that arises from the semantics of the model, only obscure it by adding a layer of indirection.<p>The coupling that should be eliminated is the reverse, ie., the inventory being unable to update stock if the notifier is down, which the article claimed was inevitable using REST. I tried to show it isn&#x27;t.<p>Regarding the message bus, I actually meant the broker, which is the SPOF being introduced in the proposed architecture.