Don't Repeat Yourself (DRY)
When writing code or designing systems
Understanding the Rule
Every piece of knowledge or logic should have a single, unambiguous representation within a system. Duplication is waste. When you need to change something, you should only need to change it in one place.
What Happens When You Break It
Violating DRY leads to bugs from inconsistent updates, wasted time hunting down all instances of duplicated code, larger codebases that are harder to understand, and technical debt that compounds over time.
Benefits of Following This Rule
DRY code is easier to maintain, has fewer bugs, is more testable, smaller in size, more understandable, and changes can be made quickly and confidently.