Imagine a quarter-long refactor: turning a big ball of mud, held together by RxSwift and 1500-line view models, into a modular, fully testable codebase. All while actively developing other features and shipping the app. What triggered that massive refactor? An innocuous estimation request. And a decision that shaped the future…
After tackling the Single Responsibility Principle and Open-Closed Principle, it's time to explore the Liskov Substitution Principle (LSP) and how it can help us write better code. At first glance, it's straightforward: if we have a component X conforming to protocol A, and another component (Y) conforming to the same…