Suggest an editImprove this articleRefine the answer for “Why does ISP simplify refactoring?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**ISP simplifies refactoring** because segregated, small interfaces create local zones of change and eliminate the cascading modifications that typically arise when working with "fat" interfaces. **Key point:** ISP reduces the scope of changes, makes the architecture clearer, reduces coupled dependencies, and allows parts of the system to be changed in isolation without touching the whole project.Shown above the full answer for quick recall.Answer (EN)ImageISP simplifies refactoring because segregated, small interfaces create **local zones of change** and eliminate the cascading modifications that typically arise when working with "fat" interfaces. In detail: ### 1. Fewer places that need to change When an interface is small and specialized, changing it only affects the implementations that actually use that contract. A "fat" interface means dozens of dependent classes, so one modified method breaks the whole project. ### 2. A more transparent architecture Small interfaces reflect clear roles ("prints", "scans", "logs"). During refactoring it is easy to identify which part of the system is responsible for what. With "fat" interfaces you have to work out which part relates to which responsibility. ### 3. Easier to reuse and swap implementations If an interface is small, one implementation can easily be replaced with another without breaking client code. This is especially important when refactoring the architecture or extracting functionality into separate services. ### 4. Avoiding unnecessary functionality in classes When a class implements only the interfaces it needs, there is no "extra" code inside it. This reduces the chance of errors when it is rewritten. ### 5. Localization of changes Small interfaces mean that a change in one functional area does not affect another. For example, a change to logging should not change the interface and classes responsible for the network API. ### 6. Stable contracts If an interface is too large, it changes often, because every team or feature affects it. When interfaces are small, they are more stable, and stable contracts are the foundation of safe refactoring. ### 7. Simplifies decomposition when moving to microservices or modules Segregated interfaces are easier to extract into separate modules - each responsible for its own "micro-function". Summary: **ISP simplifies refactoring because it reduces the scope of changes, makes the architecture clearer, reduces coupled dependencies, and allows parts of the system to be changed in isolation without touching the whole project.**For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.