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NestJS, with its modular architecture, makes applying SoC almost effortless — but understanding <em>why</em> it matters and <em>how</em> to use it properly will help you write cleaner, testable, and future-proof code.</p><h2 id=what-is-separation-of-concerns-and-why-it-matters>What is Separation of Concerns and Why it Matters?<a hidden class=anchor aria-hidden=true href=#what-is-separation-of-concerns-and-why-it-matters>#</a></h2><p>The basic idea is:</p><blockquote><p>A program should be divided into distinct sections, where each section addresses a single responsibility.</p></blockquote></div><footer class=post-footer><ul class=post-tags><li><a href=https://sauravdhakal.com.np/tags/nestjs/>Nestjs</a></li><li><a href=https://sauravdhakal.com.np/tags/typescript/>Typescript</a></li><li><a href=https://sauravdhakal.com.np/tags/architecture/>Architecture</a></li></ul><ul class=share-buttons><li><a target=_blank rel="noopener noreferrer" aria-label="share Understanding Separation of 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