A clerk waits on “is this SKU in stock?” while a separate nightly job fans a fee schedule change out to six interested services. How should those two interactions be designed?
Select an answer to reveal the explanation.
Short Explanation
A clerk asking “in stock?” needs an answer now—like asking a librarian a yes/no. Broadcasting a fee change is more like posting a notice on a bulletin board so many readers can pick it up without holding the poster hostage.
Full Explanation
Synchronous request/response is justified when the caller cannot proceed without the result. Asynchronous publication decouples publishers from every subscriber so fan-out does not block on each consumer. OCI Queue, Streaming, and Events later implement that async style; the design choice itself is whether coupling should be sync or async.