The naming decides the coupling. ReserveInventory names a recipient and expects an outcome; OrderPlaced names neither, so a second consumer can be added without touching the publisher. Past…
Every framework had an event dispatcher and none of them shared an interface, so a library that wanted to emit events either picked one or invented its own.…
Putting a cache inside a repository mixes two concerns and makes the uncached version untestable, and the alternative is a second implementation of the same interface. The decorated…
Counting failures in a PHP object means each of fifty workers keeps its own count and opens independently, which is fifty times more slow calls than intended. Using…
Four useState calls whose setters are always called together are a state machine written as four independent variables, and every transition has to remember all four. The transitions…
Passing money as an integer means every function taking it validates it, and every one of those validations needs a test — a type that refuses to exist…