When DRY Dries Out Too Soon

“Don’t Repeat Yourself.” A rule we all learn early. Yet real-world code has a way of proving that repetition, at times, is a clear, safe choice.

Duplication simplifies certain tasks. Fixing a bug in duplicated code may require several edits, but altering shared code can quietly unsettle distant parts of a system. Duplication offers localized safety, while abstraction carries global risks.

Both abstraction and duplication can be reversed, though abstractions typically cling stubbornly once established.

Sometimes identical code blocks appear similar yet carry distinct meanings. They're not twins—they’re strangers wearing the same clothes, speaking entirely different languages.

Imagine an abstraction crafted early, based on preliminary understanding. Months later, when business logic shifts, this abstraction no longer fits. Do you patch it endlessly with flags and parameters, or do you rebuild it entirely, courageously undertaking substantial refactoring?

Refactoring duplicated code has its own hazards, but it generally proves simpler than untangling bad abstractions.

A duplicated code block resembles an overly polite guest who quietly overstays their welcome. In contrast, abstraction behaves like an overly enthusiastic neighbor, linking every aspect of your project into a complex web of dependencies.

Duplication naturally emerges early, when patterns remain unclear. It’s safer than prematurely abstracting uncertain logic. Duplication may also reappear later during busy phases, when caution appropriately tempers aggressive restructuring.

Developers should duplicate intentionally to reduce dependencies and manage uncertainty. Effective abstractions emerge confidently as business logic stabilizes, providing lower maintenance costs when executed properly.

DRY is deeply ingrained: we instinctively raise eyebrows at duplication, problematic or merely redundant. Yet, in code—as in life—duplication isn't a cardinal sin. It's practical. Perhaps we might learn to appreciate its awkward charm while instinctively scolding it outright.