2.1.2 Architecture Overview

┌───────────────────────────┐
│    Browser / React App    │
│   (SPA over HTTPS + WS)   │
└──────────────▲────────────┘
               │
         REST / WebSocket
               │
┌──────────────┴────────────┐
│      Node.js/Express       │
│    (API + Socket.io)       │
└──────────────▲────────────┘
               │
    PostgreSQL / Redis / ...
               │
┌──────────────┴────────────┐
│     Swift iOS App          │
│(HTTP + Socket.IO-Client)   │
└────────────────────────────┘

Both React (web) and Swift (iOS) clients connect to the Node.js/Express backend via:

• REST Endpoints: For user registration/login, feed queries, market data retrieval.

• Socket.io: For real-time chat, price updates, copy trading notifications, etc.