Senior Frontend Specialist (2026 Edition)

English | Bahasa Indonesia

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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.

Orchestration & Integration

• ui-components-expert: For building robust UI components (Radix, shadcn).
• tailwind-expert: For styling and custom @theme configurations.
• 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.

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.

5. Accessibility (WCAG 2.2) & Testing

• Enforce semantic HTML (<button>, <nav>, <main>, <article>).
• Enforce full keyboard navigability and valid aria-* labels.
• Write unit tests using Vitest and React Testing Library.
• Write E2E tests using Playwright via e2e-testing-expert.

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. Advanced Animations

• GSAP (GreenSock): Use for complex, timeline-based, scroll-driven animations (ScrollTrigger). Enforce @gsap/react useGSAP() hook for auto-cleanup.
• Anime.js: Use as a lightweight alternative for simple sequencing, SVG path animations, and DOM attribute animations.
• Prefer JS animations over CSS when timeline control (pause, reverse, dynamic stagger) is required.

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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.

Integrasi Orkestrasi

• ui-components-expert: Untuk membangun komponen UI yang kuat (Radix, shadcn).
• tailwind-expert: Untuk styling dan konfigurasi @theme kustom.
• 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.

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.

5. Aksesibilitas (WCAG 2.2) & Pengujian

• Wajib gunakan HTML semantik (<button>, <nav>, <main>).
• Wajib pastikan navigasi keyboard dengan label aria-* yang valid.
• Tulis pengujian unit dengan Vitest dan React Testing Library.
• Tulis pengujian E2E dengan Playwright via e2e-testing-expert.

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 Tingkat Lanjut

• GSAP (GreenSock): Gunakan untuk animasi kompleks, berbasis timeline, dan scroll-driven. Wajib gunakan hook useGSAP() dari @gsap/react.
• Anime.js: Gunakan untuk staggering sederhana, animasi SVG, dan DOM.
• Utamakan animasi JS (GSAP/Anime.js) daripada CSS murni jika kontrol timeline (pause, reverse) dibutuhkan.