Node.js Architecture & V8 Engine

┌─────────────────────────────────────────┐
│           Your Node.js code             │
└────────────────┬────────────────────────┘
                 ▼
┌─────────────────────────────────────────┐
│        Node.js bindings (C++)           │
│   (fs, http, crypto, net, stream …)     │
└──┬──────────────┬──────────────┬────────┘
   ▼              ▼              ▼
┌──────┐    ┌─────────┐    ┌──────────┐
│  V8  │    │  libuv  │    │  OpenSSL │
│ (JS) │    │ (I/O,   │    │  (TLS)   │
│      │    │ thread- │    │          │
│      │    │ pool)   │    │          │
└──────┘    └─────────┘    └──────────┘

• Google's open-source JavaScript engine, also used in Chrome.
• Parses → compiles → optimises JS to machine code via JIT (Just-In-Time).
• Two compilers: Ignition (fast startup) and TurboFan (heavy optimisation).
• Garbage collector frees unused memory automatically.

• Provides the event loop + cross-platform async I/O.
• Has a default thread pool of 4 (configurable via UV_THREADPOOL_SIZE) for heavy syscalls (fs, dns, crypto.pbkdf2).