senior-frontend v4.2.0A

Immutable. This exact content never changes and is served at /api/v1/blob/d9546b44cf7182aa.

---
name: senior-frontend
description: "Frontend development for React 19, Next.js 15, TypeScript, and Tailwind CSS v4 / Pengembangan frontend dengan React 19, Next.js 15, TypeScript, dan Tailwind CSS v4."
author: "Roedy Rustam"
version: "4.2.0"
---

# Senior Frontend Specialist (2026 Edition)

[English](#english) | [Bahasa Indonesia](#bahasa-indonesia)

---

<a name="english"></a>
## English

### Description
Production-grade frontend development patterns, performance optimization, and modern ecosystem integrations for React 19 / Next.js 15 applications with Tailwind CSS v4 and TypeScript. Covers React 19 Compiler, Partial Prerendering (PPR), View Transitions API, and SPA/MPA hybrid strategies with automated self-healing testing loops.

### Orchestration & Integration
- `design-system-architect`: For building robust UI components (Radix, Base UI, shadcn) and design tokens.
- `tailwind-expert`: For styling and custom @theme configurations.
- `svg-animation-motion-expert`: For advanced animations, GSAP timelines, and motion physics.
- `nextjs-app-router-expert`: For RSC, caching, and Next.js routing patterns.
- `state-management-expert`: For client-side state (Zustand, Jotai).
- `tanstack-query-expert`: For advanced data fetching and server state caching.
- `spa-orchestrator`: For Single-Page Application architectures.
- `mpa-orchestrator`: For Multi-Page Application architectures.
- `autonomous-tdd-debugger`: For automated unit/component test execution and stack-trace self-healing.
- `anti-slop`: For enforcing complete, stub-free component implementations and zero syntax narration comments.

### Trigger Conditions
- Scaffold a new React or Next.js 15 project with TypeScript and Tailwind CSS v4.
- Generate new components, custom hooks, or Server Actions.
- Analyze and optimize bundle sizes and Core Web Vitals.
- Implement advanced React 19 patterns (`useActionState`, `useOptimistic`, `use()`).
- Build SPAs — coordinate with `spa-orchestrator`.
- Ensure accessibility compliance (WCAG 2.2) and testing.

### Technical Guidelines & Best Practices

#### 1. Next.js 15: Server vs Client Components
Use **Server Components** by default for performance and SEO. Use `'use client'` strictly for:
- State (`useState`, `useEffect`), event handlers (`onClick`), browser APIs.
- Interactive UI needing client hydration.

*Next.js 15.2+ Requirements:*
- Await `Promise`-based `params` and `searchParams` before accessing properties.
- Use **Partial Prerendering (PPR)** natively. Wrap dynamic sections in `<Suspense>`.

#### 2. React 19 Compiler & Hooks
Do not use `useMemo`, `useCallback`, or `React.memo` unless explicitly required; rely on the React 19 compiler.

**Mandatory Hooks:**
- **`useActionState`**: Manage form state, pending indicators, and action results with Server Actions.
- **`useOptimistic`**: Update UI instantly before server confirmation.
- **`useFormStatus`**: Read form submission state in child components.
- **`use(promise)`**: Unwrap promises or context inside render with Suspense.

#### 3. View Transitions API
Implement native View Transitions API for smooth page transitions. Use Next.js 15 `<Link viewTransition>` natively.

#### 4. Tailwind CSS v4
Use CSS-first configuration. Define custom tokens with `@theme` and register plugins with `@plugin` in the main CSS file. Never create `tailwind.config.js`.

#### 5. Accessibility (WCAG 2.2) & Self-Healing Testing
- Enforce semantic HTML (`<button>`, `<nav>`, `<main>`, `<article>`).
- Enforce full keyboard navigability and valid `aria-*` labels.
- Run typecheck (`tsc --noEmit`) to verify zero compiler diagnostics.
- Write unit tests using **Vitest** and **React Testing Library**.
- When tests fail, activate `autonomous-tdd-debugger` to self-heal until 100% passing.

#### 6. Architecture Integration
- **SPA (`spa-orchestrator`)**: Use **TanStack Router** for type-safe client routing and **TanStack Query v5** for server state. Never use bare `useEffect` for data fetching.
- **MPA (`mpa-orchestrator`)**: Use **Alpine.js** or **HTMX** for micro-interactions. Apply Progressive Enhancement.

#### 7. Animations & Motion
For web animations, scroll-driven timelines, GSAP choreographies, and Framer Motion spring physics, delegate directly to `svg-animation-motion-expert`.


#### 8. Material Design 3 (M3) Web Integration (https://m3.material.io/)
In modern React 19 / Next.js 15 apps, incorporate Google's official Material Web Components (`@material/web`) or token-mapped headless primitives:
- **Material Web Components**: Use Lit-based web components (`@material/web/button/filled-button.js`, `@material/web/textfield/outlined-text-field.js`) with React 19 native custom element support.
- **Dynamic CSS Variable Theming**: Map tokens dynamically at the root:
```tsx
'use client';

import '@material/web/button/filled-button.js';
import '@material/web/elevation/elevation.js';

export function M3ActionButton({ label, onClick }: { label: string; onClick: () => void }) {
  return (
    <div className="relative inline-flex">
      <md-filled-button onClick={onClick} className="m3-button">
        {label}
      </md-filled-button>
    </div>
  );
}
```

---

<a name="bahasa-indonesia"></a>
## Bahasa Indonesia

### Deskripsi
Pola pengembangan frontend tingkat produksi, optimasi performa, dan integrasi ekosistem modern untuk aplikasi React 19 / Next.js 15 dengan Tailwind CSS v4 dan TypeScript. Mencakup React 19 Compiler, Partial Prerendering (PPR), View Transitions API, dan strategi hybrid SPA/MPA dengan loop pengujian perbaikan mandiri (self-healing).

### Integrasi Orkestrasi
- `design-system-architect`: Untuk membangun komponen UI yang kuat (Radix, Base UI, shadcn) dan design token.
- `tailwind-expert`: Untuk styling dan konfigurasi @theme kustom.
- `svg-animation-motion-expert`: Untuk animasi web, timeline GSAP, dan fisika spring.
- `nextjs-app-router-expert`: Untuk RSC, caching, dan pola routing Next.js.
- `state-management-expert`: Untuk state client-side (Zustand, Jotai).
- `tanstack-query-expert`: Untuk fetching data lanjutan dan caching server state.
- `spa-orchestrator`: Untuk arsitektur Single-Page Application.
- `mpa-orchestrator`: Untuk arsitektur Multi-Page Application.
- `autonomous-tdd-debugger`: Untuk eksekusi pengujian otomatis dan perbaikan mandiri berdasarkan stack trace terminal.

### Kondisi Pemicu
- Buat proyek React atau Next.js 15 baru dengan TypeScript dan Tailwind CSS v4.
- Buat komponen baru, custom hooks, atau Server Actions.
- Analisis dan optimalkan ukuran bundle dan Core Web Vitals.
- Terapkan pola React 19 lanjutan (`useActionState`, `useOptimistic`, `use()`).
- Bangun SPA — koordinasikan dengan `spa-orchestrator`.
- Pastikan kepatuhan aksesibilitas (WCAG 2.2) dan pengujian.

### Panduan Teknis & Praktik Terbaik

#### 1. Next.js 15: Server vs Client Components
Gunakan **Server Components** secara default. Gunakan `'use client'` hanya untuk:
- State (`useState`, `useEffect`), event handler, API browser.
- UI interaktif yang membutuhkan hidrasi klien.

*Persyaratan Next.js 15.2+:*
- Wajib `await` pada `params` dan `searchParams` yang kini bertipe `Promise`.
- Gunakan **Partial Prerendering (PPR)** secara native. Bungkus bagian dinamis dengan `<Suspense>`.

#### 2. React 19 Compiler & Hook Baru
Jangan gunakan `useMemo`, `useCallback`, atau `React.memo` kecuali sangat diperlukan; andalkan compiler React 19.

**Hook Wajib:**
- **`useActionState`**: Kelola state form, indikator loading, dan hasil action dengan Server Actions.
- **`useOptimistic`**: Perbarui UI secara instan sebelum server mengonfirmasi.
- **`useFormStatus`**: Baca status form di dalam komponen anak.
- **`use(promise)`**: Buka promise atau context langsung di dalam render dengan Suspense.

#### 3. View Transitions API
Terapkan View Transitions API bawaan browser untuk transisi halaman. Gunakan `<Link viewTransition>` pada Next.js 15.

#### 4. Tailwind CSS v4
Gunakan konfigurasi CSS-first. Definisikan token kustom dengan `@theme` dan plugin dengan `@plugin` di file CSS utama (lihat `tailwind-expert`). Jangan pernah membuat file `tailwind.config.js`.

#### 5. Aksesibilitas (WCAG 2.2) & Pengujian Self-Healing
- Wajib gunakan HTML semantik (`<button>`, `<nav>`, `<main>`).
- Wajib pastikan navigasi keyboard dengan label `aria-*` yang valid.
- Jalankan pemeriksaan tipe (`tsc --noEmit`) untuk memastikan nol eror diagnostik.
- Tulis pengujian unit dengan **Vitest** dan **React Testing Library**.
- Jika pengujian gagal, aktifkan `autonomous-tdd-debugger` untuk memulihkan kode hingga 100% lolos.

#### 6. Integrasi Arsitektur
- **SPA (`spa-orchestrator`)**: Gunakan **TanStack Router** untuk routing klien dan **TanStack Query v5** untuk server state. Jangan gunakan `useEffect` murni untuk fetching data.
- **MPA (`mpa-orchestrator`)**: Gunakan **Alpine.js** atau **HTMX** untuk interaksi mikro. Terapkan Progressive Enhancement.

#### 7. Animasi & Motion
Untuk animasi web, timeline scroll-driven, koreografi GSAP, dan fisika spring Framer Motion, delegasikan langsung ke `svg-animation-motion-expert`.

#### 8. Integrasi Web Material Design 3 (M3) (https://m3.material.io/)
Pada aplikasi React 19 / Next.js 15 modern, terapkan komponen web resmi Google (`@material/web`) atau primitif headless yang dipetakan ke token M3:
- **Komponen Material Web**: Manfaatkan komponen berbasis Lit (`@material/web`) yang didukung secara native oleh React 19 tanpa wrapper tambahan.
- **Theming Variabel CSS Dinamis**: Terapkan token M3 (`--md-sys-color-primary`, `--md-sys-color-surface-container`) pada elemen root untuk menjamin paritas kontras WCAG di seluruh komponen antarmuka.