Runtime — JavaScript & TypeScript Runtimes

Status: Active Last Updated: 2026-08-29 Category: Runtimes & Execution Environments Prerequisites: kb/languages/ — TypeScript basics Tags: bun, node, deno, runtime, javascript, typescript, server

Summary

How JavaScript and TypeScript execute — the runtimes, the event loop, module systems, and how to deploy and run code outside the browser. This stack uses Bun as the primary runtime (fast, all-in-one, native TypeScript support).

🎯 Learning Philosophy

Why Runtimes Matter:

Browser:  V8 engine (Chrome/Edge) → DOM APIs
Node:     V8 engine → server-side APIs (fs, net, http)
Bun:      JavaScriptCore engine → all-in-one (install + test + build + serve)
Deno:     V8 engine → secure-by-default, built-in TypeScript

📚 Learning Path

Prerequisites: kb/languages/typescript-basics
         ↓
┌────────────────────────────────────────┐
│  PHASE 1: Bun Fundamentals             │
│  ├─ What is Bun                       │
│  ├─ Bun install, run, test, build       │
│  ├─ Bun.serve() and native HTTP        │
│  └─ Bun vs Node vs Deno               │
└────────────────────────────────────────┘
         ↓
┌────────────────────────────────────────┐
│  PHASE 2: Node.js Fundamentals        │
│  ├─ Node architecture (V8 + libuv)     │
│  ├─ CJS vs ESM module systems          │
│  ├─ npm / pnpm / yarn                 │
│  └─ Event loop and async patterns      │
└────────────────────────────────────────┘
         ↓
┌────────────────────────────────────────┐
│  PHASE 3: Runtime Internals           │
│  ├─ The event loop                     │
│  ├─ Worker threads and WASM            │
│  ├─ Hot startup, JIT compilation        │
│  └─ When to use Bun vs Node           │
└────────────────────────────────────────┘

📖 Articles in This Directory

🟢 Phase 1: Bun

1. bun-runtime — Bun as the primary runtime
   • bun install, bun run, bun test, bun build
   • Bun.serve() for HTTP servers
   • Bun SQLite, Bun.file(), Bun.$() shell
   • Bun vs Node vs Deno comparison
   • Prerequisites: TypeScript basics
   • Time: 2-3 hours

🟡 Phase 2: Node.js

1. nodejs-runtime — Node.js deep dive
   • V8 + libuv architecture
   • CJS (require) vs ESM (import)
   • npm, pnpm, yarn package managers compared
   • Event loop phases and microtasks
   • Prerequisites: TypeScript or JavaScript basics
   • Time: 3-4 hours

🟠 Phase 3: Runtime Internals

1. runtime-internals — How runtimes work
   • Event loop: call stack, task queue, microtask queue
   • Worker threads, cluster module
   • WASM integration
   • JIT compilation basics
   • When to choose Bun vs Node vs Deno
   • Prerequisites: Node or Bun experience
   • Time: 3-4 hours

🔗 What Comes Next?

• kb/backend/ — Building HTTP servers and APIs with these runtimes
• kb/containers/ — Packaging runtimes in containers
• kb/infrastructure/ — Deploying runtimes to production

📝 Change Log

2026-08-29

• Created runtime/ directory scaffold
• Defined 3-phase learning path
• Bun is primary runtime for this stack