Code Architecture: Avoiding Wrong Abstractions

Core Principle

Prefer duplication over the wrong abstraction. Wait for patterns to emerge before abstracting.

Premature abstraction creates confusing, hard-to-maintain code. Duplication is far cheaper to fix than unwinding a wrong abstraction.

The Rule of Three

Don't abstract until code appears in at least 3 places. This provides enough context to identify genuine patterns vs coincidental similarities.

// ✅ Correct: Wait for the pattern to emerge
// First occurrence - just write it
const userTotal = items.reduce((sum, item) => sum + item.price, 0);

// Second occurrence - still duplicate
const cartTotal = products.reduce((sum, p) => sum + p.price, 0);