Software Design Principles: 1.DRY (Don’t Repeat Yourself) Have you ever copied a block of code, pasted it somewhere else, and changed just one or two lines? We’ve all done it. It feels like the quickest solution — until you need to update that logic later and realize it’s duplicated in five different places. That’s exactly the problem the DRY (Don’t Repeat Yourself) principle helps solve. DRY is a simple idea: if the same logic is repeated in multiple places, it probably belongs in one reusable place. Instead of copying code, extract it into a function, component, custom hook, utility, or module that can be reused wherever it’s needed. Why does DRY matter? Following DRY makes your codebase much easier to work with over time. Less duplicate code— You write the logic once instead of repeating it everywhere.Easier maintenance— Fixes and improvements only need to be made in one place.Single point of change— There’s one source of truth for a piece of logic.Better readability— Small, reusable functions and components are easier to understand.Fewer bugs— Since there’s only one implementation, you don’t have to worry about different copies behaving differently. <b>Where can you apply DRY?</b> You can use the DRY principle almost anywhere: Extract repeated logic into afunction.Create acustom React Hookfor shared React logic.Build areusable componentinstead of duplicating UI.Move common helper logic into autility function.Share business logic through aservice or module. One thing to remember DRY doesn’t mean you should create an abstraction the moment you see two similar lines of code. Sometimes duplication is temporary, and forcing an abstraction too early can make your code harder to understand. A good approach is to let patterns emerge naturally. Once you notice the same logic being used in multiple places and it’s likely to stay that way, that’s the right time to extract it into something reusable. “Every piece of knowledge should have a single, unambiguous, authoritative representation within a system.” — The Pragmatic Programmer 2. KISS (Keep It Simple, Stupid) The KISS (Keep It Simple, Stupid) principle reminds us to keep our code as simple as possible. When solving a problem, choose the simplest solution that works instead of adding unnecessary complexity. Why does KISS matter? Faster developmentEasier debuggingBetter readabilityEasier maintenanceFewer bugs 3. YAGNI (You Aren’t Gonna Need It) As developers, we often think, “This feature might be useful in the future, so let me build it now.” While that sounds like a good idea, it usually leads to extra code that no one uses. The YAGNI (You Aren’t Gonna Need It) principle says: ……Don’t build a feature until it’s actually needed…… Instead of trying to predict the future, focus on building what solves the current problem. If a new requirement comes later, you can always add it then. Why does YAGNI matter? Prevents unnecessary codeSaves development timeKeeps the codebase simpleMakes maintenance easierReduces over-engineering When should you not use YAGNI? YAGNI doesn’t mean ignoring known requirements. If a feature is already part of the project requirements or is required for the current release, you should implement it. For example: The client requires email verification before launch. Build it now. You also add social login, multi-language support, and dark mode because they might be useful someday. The difference is simple: Known requirement → Build it.Future assumption → Don’t build it yet. Every developer writes messy code at some point — that’s part of learning. What makes us better is continuously improving our code by following simple principles like DRY, KISS, and YAGNI
