---
id: wiki-2026-0508-judgment
title: Judgment
category: 10_Wiki/Topics
status: verified
canonical_id: self
aliases: [Engineering Judgment, Trade-off Judgment, Frontend Judgment]
duplicate_of: none
source_trust_level: A
confidence_score: 0.9
verification_status: applied
tags: [judgment, engineering, decision-making, frontend]
raw_sources: []
last_reinforced: 2026-05-10
github_commit: pending
tech_stack:
  language: meta
  framework: meta
---

# Judgment

## 매 한 줄
> **"매 좋은 frontend 는 매 framework choice 가 아니라 매 trade-off 의 매 명시적 분석에서 나온다."**. Performance / DX / accessibility / bundle size / SEO 의 매 weight 가 매 product context 에 따라 매 다르다. Judgment 는 매 가르칠 수 있는 skill — checklist + heuristic.

## 매 핵심

### 매 Trade-off 축
- **Performance vs DX**: SSR + island vs CSR SPA.
- **Bundle vs Feature**: tree-shake-able lib vs all-in-one.
- **Type safety vs Velocity**: strict TS vs JS prototyping.
- **A11y vs Custom**: native element vs custom component.
- **Cache vs Freshness**: SWR vs no-store.

### 매 Heuristic
1. **Native first**: 매 platform primitive 가 매 free win.
2. **Measure before optimize**: 매 Lighthouse / RUM 먼저.
3. **Latency budget**: 매 LCP < 2.5s, INP < 200ms, CLS < 0.1 (Core Web Vitals 2026).
4. **Bundle budget**: 매 route 당 매 100KB gzip.
5. **Dependency cost**: 매 add 마다 매 maintenance + bundle + supply chain risk.

### 매 Decision framework
- **Reversible vs One-way door**: framework choice = one-way. 매 careful.
- **Time horizon**: 매 6 개월 vs 매 5 년 — 매 다른 답.
- **Team skill**: 매 unfamiliar tech 의 매 hidden cost.

### 매 응용
1. SSR vs CSR — 매 SEO / TTI / DX matrix.
2. State manager 선택 — 매 server vs client state 분리.
3. CSS strategy — 매 atomic / module / runtime.

## 💻 패턴

### Decision matrix template (Markdown)
```markdown
| 기준 | Option A | Option B | Weight |
|---|---|---|---|
| Bundle size | 12KB | 45KB | 0.3 |
| DX | High | Medium | 0.2 |
| Maintenance | Active | Stale | 0.3 |
| TS support | Native | Patchy | 0.2 |
| **Score** | 0.84 | 0.51 | — |
```

### Bundle budget enforcement (CI)
```javascript
// vite.config.ts
export default {
  build: {
    rollupOptions: {
      output: { manualChunks: { vendor: ['react', 'react-dom'] } },
    },
    chunkSizeWarningLimit: 100,   // KB
  },
};
// Then: bundlesize / size-limit in CI
```

### Performance budget gate
```yaml
# .github/workflows/perf.yml
- name: Lighthouse CI
  uses: treosh/lighthouse-ci-action@v12
  with:
    urls: |
      https://staging.example.com/
    budgetPath: ./budget.json
    assertions: |
      categories.performance: ['error', { minScore: 0.9 }]
      audits.largest-contentful-paint: ['error', { maxNumericValue: 2500 }]
      audits.interaction-to-next-paint: ['error', { maxNumericValue: 200 }]
```

### Feature flag for risky migration
```typescript
import { useFlag } from '@/lib/flags';
function Page() {
  const useNewRouter = useFlag('new-router-2026');
  return useNewRouter ? <NextAppRouter /> : <PagesRouter />;
}
```

### A11y default vs custom
```tsx
// PREFER native
<button onClick={...}>Save</button>

// Avoid custom unless necessary
<div role="button" tabIndex={0} onKeyDown={handle}>...</div>
```

### Reversibility check
```markdown
- [ ] Can we roll back in 1 day? (file flag, env var)
- [ ] Can we roll back in 1 week? (revert PR)
- [ ] One-way door? (DB schema, public API) — 매 RFC 필수
```

## 매 결정 기준
| 상황 | Approach |
|---|---|
| 매 SEO 우선 | SSR / SSG (Next.js, Astro, SvelteKit) |
| 매 dashboard (auth-only) | CSR SPA (Vite + React) |
| 매 content site | Astro / 11ty (zero JS default) |
| 매 realtime collaborative | CSR + WebSocket / CRDT |
| 매 mobile app | RN / Expo (Hermes) |
| 매 desktop app | Tauri (Rust) > Electron |

**기본값**: 매 measure → matrix → smallest reversible step.

## 🔗 Graph
- 변형: [[ADR]]
- 응용: [[Large_Frontend_Projects|Frontend Architecture]]
- Adjacent: [[Core Web Vitals Optimization (INP, LCP 개선)|Core Web Vitals]] · [[Accessibility (A11y)|Accessibility]] · [[DX]]

## 🤖 LLM 활용
**언제**: 매 framework / library 선택 시, 매 RFC 작성, 매 trade-off 명시화.
**언제 X**: 매 obvious choice — 매 over-engineering.

## ❌ 안티패턴
- **Resume-driven development**: 매 새로운 tech 만 추구.
- **Unmeasured optimization**: 매 perf 직감 만.
- **Cargo cult**: 매 big company 가 사용 = 매 우리에게 맞다 X.
- **Analysis paralysis**: 매 endless matrix — 매 timebox.

## 🧪 검증 / 중복
- Verified (Core Web Vitals 2026 thresholds, ADR template).
- 신뢰도 A.

## 🕓 Changelog
| 날짜 | 변경 |
|---|---|
| 2026-05-08 | Phase 1 |
| 2026-05-10 | Manual cleanup — 매 trade-off matrix + budget pattern |
