Even the best event / data streaming architecture (or, more generally, a backend architecture) in the universe can be negated by a lousy frontend app / frontend

Even the best event / data streaming architecture (or, more generally, a backend architecture) in the universe can be negated by a lousy frontend app / frontend layer architecture. I have never ordered anything from a Macca's… but I surmise that is the consequences that McDonald app users are facing. The article lacks any details material to the event streaming architecture instantiation, and defers the details to a follow-up blog post, so it is hard to draw meaningful conclusions from it.