AI can write code. Fast. Quality depends on who’s directing it.
So what separates software that works from software that lasts?
The Formula
Quality = Performance × Reliability × Maintainability × Security
Not additive. Multiplicative. One zero kills everything.
Good: 90 × 85 × 80 × 75 = 45,900,000 Bad: 95 × 90 × 88 × 0 = 0
The Factors
Performance ├── Does it feel fast? ├── Initial load, runtime, bundle size └── Perception matters — skeleton screens, optimistic updates Reliability ├── Can you trust it? ├── Tests catch what broke ├── Types catch what doesn't fit └── Resilience catches what fails Maintainability ├── Can the next dev understand this? ├── Readability, modularity, predictability └── Change one file → one file changes, not seven Security ├── Is it safe? ├── Validate → Sanitize → Escape └── Never trust user input
The Reality
Performance: ████████░░ 90% Reliability: ████████░░ 85% Maintainability: ████████░░ 80% Security: ███░░░░░░░ 30% ← ceiling
The weakest factor dominates. Can’t offset poor security with great performance.
Quality is a multiplier, not a sum.