```mermaid flowchart TB subgraph ITCSS_Layers["ITCSS Cascade Layers"] direction TB L1["1️⃣ Settings — Custom properties, tokens"] L2["2️⃣ Tools — Mixins, functions"] L3["3️⃣ Generic — Reset, normalize"] L4[

--- name: nextjs-mastery category: coding description: >- Comprehensive Next.js skill covering App Router architecture, rendering strategies, data fetching patterns, security hardening, testing, and production deployment. version: "1.0.0" tags:

Comprehensive PHP mastery covering modern PHP 8+, OOP & design patterns, security, frameworks, database/ORM, testing, performance, deployment, and production operations.

--- name: react-mastery category: coding description: "React mastery: hooks deep dive, state management, component patterns, security, performance optimization, and testing." version: 1.0.0 tags: [react, hooks, state-management, components, security,

### Control Plane Components

### Four-Step Framework ``` Step 1: REQUIREMENTS ──→ Functional + Non-Functional (QPS, latency, storage, availability) Step 2: ESTIMATION ───→ Back-of-envelope: users × requests × data size × redundancy Step 3: HIGH-LEVEL ───→ Draw architecture with