Why is Swift ABI Stability a Big Deal?

This article explains the concept of ABI (Application Binary Interface) stability in Swift, a major milestone for the language. It describes the problem before ABI stability: frameworks compiled with one Swift version could not communicate with apps compiled with another, requiring recompilation. With ABI stability (introduced in Swift 5), frameworks compiled with Swift 5.0 can work with apps compiled with Swift 5.1 or later, enabling binary compatibility. The article emphasizes understanding the why behind the feature, targeting developers interested in Swift, iOS/macOS development, and software engineering best practices.