https://nalar.dev/tags/object-design/ Recent content in Object Design on Nalar Hugo en-us Thu, 03 Sep 2026 00:00:00 +0700 https://nalar.dev/put-decisions-next-to-the-data-they-need/ Thu, 03 Sep 2026 00:00:00 +0700 https://nalar.dev/put-decisions-next-to-the-data-they-need/ <p>A method can look perfectly reasonable while depending on far more knowledge than it should.</p> <p>Imagine checkout code that asks a customer object for <code>membershipLevel</code>, <code>joinedAt</code>, and <code>totalOrders</code>, then combines those values to decide whether the customer receives priority support. The calculation works, but checkout now knows both the customer&rsquo;s data and the rule that gives that data meaning.</p> <p>When the rule changes, every caller that reconstructed it becomes a possible edit site.</p>