Feature Flag

علم الميزة

Intermediatedevops1 min read
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Definition

A configuration value that enables or disables a feature in production without deploying new code — allowing gradual rollouts and safe testing of new features.

قيمة تكوين تُمكّن أو تُعطّل ميزة في الإنتاج دون نشر كود جديد — مما يسمح بإطلاق تدريجي وتجربة آمنة للميزات الجديدة.

Why It Matters

Sprint 5 features (AI Teacher, AI Builder) must not be visible to public users until they are ready. Feature flags let Omar deploy the code to production, test it internally, and flip the flag to enable it for everyone — without a new deployment. This is how professional teams ship features confidently.

ميزات Sprint 5 (AI Teacher وAI Builder) يجب ألا تكون مرئية للمستخدمين العامين حتى تصبح جاهزة. تسمح أعلام الميزات لعمر بنشر الكود للإنتاج واختباره داخلياً وتبديل العلم لتمكينه للجميع — دون نشر جديد. هكذا تُطلق الفرق الاحترافية الميزات بثقة.

Full Definition

A feature flag is a conditional in your code that checks a configuration value to determine whether to enable a feature: `if (process.env.FEATURE_AI_TEACHER_ENABLED === 'true') { renderAITeacher(); }`. Flags enable: gradual rollouts (enable for 10% of users, then 50%, then 100%), A/B testing, kill switches (instantly disable a broken feature without deployment), and environment-specific behavior (AI Teacher enabled in staging, disabled in production). 404Fault uses `FEATURE_AI_TEACHER_ENABLED` and `FEATURE_AI_BUILDER_ENABLED` as Vercel environment variables.
علم الميزة هو شرط في كودك يتحقق من قيمة تكوين لتحديد ما إذا كان سيُمكّن ميزة: `if (process.env.FEATURE_AI_TEACHER_ENABLED === 'true') { renderAITeacher(); }`. تُمكّن الأعلام: الإطلاقات التدريجية (تمكين لـ 10% من المستخدمين ثم 50% ثم 100%) واختبار A/B ومفاتيح القتل (تعطيل ميزة معطوبة فوراً دون نشر) والسلوك الخاص بالبيئة (AI Teacher ممكّن في التدريج، معطّل في الإنتاج). يستخدم 404Fault `FEATURE_AI_TEACHER_ENABLED` و`FEATURE_AI_BUILDER_ENABLED` كمتغيرات بيئة Vercel.

Example Usage

In Next.js: `// src/lib/features.ts export const FEATURES = { AI_TEACHER: process.env.FEATURE_AI_TEACHER_ENABLED === 'true', AI_BUILDER: process.env.FEATURE_AI_BUILDER_ENABLED === 'true', } as const;`. Usage: `if (FEATURES.AI_TEACHER) { return <AITeacherPanel />; }`. Toggle in Vercel dashboard without redeployment.

في Next.js: `// src/lib/features.ts export const FEATURES = { AI_TEACHER: process.env.FEATURE_AI_TEACHER_ENABLED === 'true', AI_BUILDER: process.env.FEATURE_AI_BUILDER_ENABLED === 'true', } as const;`. الاستخدام: `if (FEATURES.AI_TEACHER) { return <AITeacherPanel />; }`. التبديل في لوحة Vercel دون إعادة نشر.

Knowledge Graph

Avoid these mistakes when using Feature Flag:

1

Leaving feature flags in code indefinitely — flags are temporary; clean up old flags after full rollout or removal

2

Checking feature flags in shared library code — flag checks in a shared `lib/` function make the logic harder to trace; check at the component/route level

3

Not adding the flag to documentation — if a flag exists in production and a new engineer doesn't know about it, they cannot debug related behavior

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Help me build a project using Feature Flag.

Explain:
1. What is Feature Flag and why it matters
2. The core architecture and required tools
3. Step-by-step implementation plan
4. Common mistakes to avoid: Leaving feature flags in code indefinitely — flags are temporary; clean up old flags after full rollout or removal, Checking feature flags in shared library code — flag checks in a shared `lib/` function make the logic harder to trace; check at the component/route level, Not adding the flag to documentation — if a flag exists in production and a new engineer doesn't know about it, they cannot debug related behavior
5. Best practices and production tips

Official Resources