{"id":1298,"date":"2025-08-12T13:36:15","date_gmt":"2025-08-12T06:36:15","guid":{"rendered":"https:\/\/kienthucmo.com\/kiss-dry-yagni-3-golden-principles-in-software-development\/"},"modified":"2025-12-09T23:07:46","modified_gmt":"2025-12-09T16:07:46","slug":"kiss-dry-yagni-3-golden-principles-in-software-development","status":"publish","type":"post","link":"https:\/\/kienthucmo.com\/en\/kiss-dry-yagni-3-golden-principles-in-software-development\/","title":{"rendered":"KISS, DRY, YAGNI – 3 Golden Principles in Software Development"},"content":{"rendered":"\n

In the world of software, where every line of code can be the “seed” for a robust system or a “time bomb” of errors, we \u2014 the developers \u2014 need more than just the ability to write working code. We need to write code that is readable, maintainable, and won’t become a burden in the future.<\/p>\n\n\n\n

The three principles KISS<\/strong>, DRY<\/strong>, and YAGNI<\/strong> are a “guiding trio” that have existed and proven their value over decades. They are not just empty slogans, but the distilled essence of hard-earned experience from countless successful software projects… and failures as well.<\/p>\n\n\n\n

In this article, we will delve into the meaning, mindset behind, and practical application of these three principles. Consider this not just as knowledge, but as the survival philosophy of a programmer.<\/p>\n\n\n\n

1. Overview<\/h2>\n\n\n\n

KISS, DRY, and YAGNI are commonly referred to as “software design principles”<\/strong> or more specifically as “programming principles”<\/strong> (programming principles \/ coding principles).<\/p>\n\n\n\n

They belong to the “best practices”<\/strong> group \u2013 methods and principles widely recognized to help make code more maintainable, scalable, and error-resistant.
<\/p>\n\n\n\n

\"Software<\/figure>\n\n\n\n

In addition to these three principles, developers often refer to other principles such as:\n<\/p>\n\n\n\n

    \n
  • SOLID<\/strong> \u2013 5 object-oriented design principles.<\/li>\n\n\n\n
  • GRASP<\/strong> \u2013 Principles of responsibility assignment in OOP.<\/li>\n\n\n\n
  • SoC<\/strong> (Separation of Concerns) \u2013 Separate functionalities for easier management.<\/li>\n\n\n\n
  • SNE<\/strong> (Simple, Not Easy) \u2013 similar to KISS but focuses on “simplicity without compromising quality.”<\/li>\n\n\n\n
  • Occam\u2019s Razor<\/strong> \u2013 Choose the simplest solution possible that still meets the requirements.<\/li>\n\n\n\n
  • Fail Fast<\/strong> \u2013 Detect errors as early as possible to reduce repair costs.<\/li>\n<\/ul>\n\n\n\n

    In this article, we will focus primarily on KISS, DRY, and YAGNI.\n<\/p>\n\n\n\n

    2. KISS \u2014 Keep It Simple, Stupid<\/h2>\n\n\n
    \n
    \"\"<\/figure>\n<\/div>\n\n\n

    2.1 Definition & Philosophy<\/h3>\n\n\n\n

    KISS is a reminder to: Keep everything as simple as possible<\/strong>. In system design and coding, \u201csimple\u201d does not mean removing features, but rather avoiding unnecessary complexity<\/strong>.<\/p>\n\n\n\n

    Complex systems often arise from the accumulation of small but uncontrolled decisions. A function that was originally just 10 lines can, after several \u201cpatches,\u201d turn into 200 lines with many branches, forcing the reader to spend hours trying to understand it.\n<\/p>\n\n\n\n

    2.2 Why is KISS important?<\/h3>\n\n\n\n
      \n
    • Speed of understanding and maintenance<\/strong>: Simple code helps new developers joining the project quickly grasp it.<\/li>\n\n\n\n
    • Reduced risk of errors<\/strong>: Every redundant piece of logic is an opportunity for a bug to appear.<\/li>\n\n\n\n
    • Optimized scalability<\/strong>: A simple platform makes it easier to add features compared to a tangled one.<\/li>\n<\/ul>\n\n\n\n

      2.3 Principles of application<\/h3>\n\n\n\n
        \n
      • Always ask: \u201cIs there a shorter and clearer way?\u201d<\/em><\/li>\n\n\n\n
      • Avoid \u201cpremature optimization\u201d (premature optimization<\/em>).<\/li>\n\n\n\n
      • Use familiar structures and libraries instead of \u201cinventing\u201d things that no one understands.\n<\/li>\n<\/ul>\n\n\n\n

        2.4 Example<\/h3>\n\n\n\n

        Problem: Calculate the total order value (including discount and tax)<\/strong>
        You have a list of products in the cart, each product has:<\/p>\n\n\n\n

          \n
        • price<\/code>: price<\/li>\n\n\n\n
        • quantity<\/code>: quantity<\/li>\n\n\n\n
        • May have discount<\/code> (optional)<\/li>\n\n\n\n
        • VAT is 10%
          Goal: Calculate the total amount the customer has to pay.<\/li>\n<\/ul>\n\n\n\n

          \u274c Complex approach, violating KISS<\/strong><\/p>\n\n\n\n

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