git:20260816.d23736e to v3.0.0

+ ---

+ name: feature-flag-analytics-expert

+ description: "Expert guide for Feature Flags & Progressive Rollout (PostHog, LaunchDarkly, GrowthBook), A/B testing orchestration, and canary releases / Panduan ahli Feature Flags, A/B testing, dan rilis bertahap."

+ author: "Roedy Rustam"

+ version: "3.0.0"

+ ---

+

+ # Feature Flag & Progressive Rollout Expert

+

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

+

+ ---

+

+ <a name="english"></a>

+ ## English

+

+ ### Purpose & Overview

+ Production-grade guidelines for feature flag management, progressive feature rollouts, canary deployments, A/B testing experiment analysis, and dynamic server-side/client-side feature evaluation using PostHog, LaunchDarkly, and GrowthBook.

+

+ ### Key Capabilities

+ - **Feature Gating**: Decoupling code deployment from feature release with instant kill-switches.

+ - **Canary & Percentage Rollout**: Incrementally releasing new features to 5%, 25%, 50%, and 100% of user segments.

+ - **Experimentation Engine**: Statistical A/B testing with conversion metrics and variant analytics.

+

+ ```typescript

+ import { PostHog } from 'posthog-node';

+

+ const posthog = new PostHog(process.env.POSTHOG_API_KEY!);

+

+ export async function isNewCheckoutEnabled(userId: string) {

+ const isEnabled = await posthog.isFeatureEnabled('new-checkout-flow', userId);

+ return isEnabled;

+ }

+ ```

+

+ ### Implementation Checklist

+ - [ ] Initialize the Feature Flag client (e.g., PostHog/LaunchDarkly) securely on the server and client.

+ - [ ] Create flags in the dashboard before referencing them in code.

+ - [ ] Set fallback (default) values for flags in case of network failures.

+ - [ ] Use user identification (User ID/Distinct ID) consistently to ensure the same user gets the same flag variant.

+ - [ ] Clean up obsolete flags from the codebase once a feature is 100% rolled out.

+

+ ## Orchestration & Integration

+ - Integrates with: `data-telemetry-expert`, `e2e-testing-expert`, `ci-cd-devops-architect`.

+

+ ---

+

+ <a name="bahasa-indonesia"></a>

+ ## Bahasa Indonesia

+

+ ### Deskripsi

+ Panduan tingkat produksi untuk manajemen feature flags, rilis fitur bertahap (progressive rollout), canary deployment, pengujian A/B testing, dan evaluasi fitur dinamis menggunakan PostHog, LaunchDarkly, dan GrowthBook.

+

+ ### Fitur Utama

+ - **Feature Gating**: Memisahkan deployment kode dari rilis fitur dengan tombol *kill-switch* instan.

+ - **Rilis Bertahap (Canary)**: Meluncurkan fitur baru secara bertahap ke 5%, 25%, 50%, hingga 100% segmen pengguna.

+ - **Mesin Eksperimen**: Pengujian A/B statistik dengan metrik konversi dan analitik varian.

+

+ ### Checklist Implementasi

+ - [ ] Inisialisasi klien Feature Flag (misal: PostHog/LaunchDarkly) secara aman di server dan klien.

+ - [ ] Buat flag di dasbor sebelum mereferensikannya dalam kode.

+ - [ ] Tetapkan nilai fallback (default) untuk flag sebagai antisipasi kegagalan jaringan.

+ - [ ] Gunakan identifikasi pengguna (User ID/Distinct ID) secara konsisten untuk memastikan pengguna yang sama mendapat varian flag yang sama.

+ - [ ] Bersihkan flag yang kedaluwarsa dari basis kode setelah fitur 100% dirilis.

+

+ ## Integrasi Orkestrasi