Web Development

Node.js Deep Dive

26-module Node.js course for engineers - from V8 + libuv + the event loop through Express, databases, testing, security, deployment, microservices, advanced patterns, and a working Link-in-Bio capstone.

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Node.js Deep Dive

This isn't an Express tutorial. It's a 26-module Node.js curriculum built around how Node is actually used in production - runtime fundamentals plus the depth most platforms never reach: the V8 / libuv / event-loop architecture, the module system from CommonJS to ESM, building HTTP servers from scratch before reaching for a framework, the Streams API as a paradigm not a footnote, the network APIs at the level senior engineers actually use them.

You'll work through the fundamentals (history, JavaScript refresher, internals, modules, HTTP from scratch, core APIs for file system / streams / network), the everyday tools (HTTP frameworks with Express and friends, databases, testing, debugging, performance), the production engineering depth (error handling and logging, security, building APIs, real-time applications, TypeScript), and the depth that separates mid from senior offers (deployment, microservices, tooling, advanced patterns, the 2026 ecosystem, interview prep) - closing with a dedicated capstone module that walks through building a complete Link-in-Bio production service end-to-end.

Every module and every topic in this course is free. The capstone deliverable (Fastify + Postgres + Redis + BullMQ) is checked into the repo alongside the lessons.

What you will learn

• Node.js fundamentals from the engineer's perspective — V8, libuv, the event loop, modules, packages
• Building HTTP servers from scratch and then with Express / Fastify
• The core APIs: file system, streams, network — used the way senior engineers use them
• Working with databases (PostgreSQL, Redis, MongoDB) and queues (BullMQ)
• Testing, debugging, profiling, and performance engineering in Node.js
• Production engineering: error handling, structured logging, security, deployment, observability
• Building production APIs (REST + GraphQL) and real-time applications (WebSocket, SSE)
• TypeScript in Node.js, microservices, advanced patterns, and the 2026 ecosystem
• Working capstone: a full Link-in-Bio service with Fastify, Postgres, Redis, BullMQ, Docker

Prerequisites

• Intermediate JavaScript familiarity (variables, async/await, modules)

Course outline

Module 1: Node.js History & Philosophy

Node.js History & Philosophy — 5 topics.

• Why This Course Exists, Why I'm Teaching It 7 min read
• Before Node: JavaScript in the Browser, Server-Side Stagnation 9 min read
• Ryan Dahl's 2009 Talk, and Why He Was Right 12 min read Pro lesson
• Node.js Today (2026): Where It Fits, Where It Doesn't 12 min read Pro lesson
• Setup: Installing Node, the REPL, the First Program 11 min read

Module 2: JavaScript Refresher for Node Developers

JavaScript Refresher for Node Developers — 6 topics.

• Closures, Really: In the Context of Node Callbacks 13 min read
• `this`, `bind`, `call`, `apply`: Node Patterns 11 min read Pro lesson
• Promises Under the Hood 13 min read Pro lesson
• async/await: The Syntactic Sugar With Sharp Edges 12 min read Pro lesson
• Modules History: A Brief Tour of How We Got Here 13 min read Pro lesson
• Iterators, Generators, Async Iterators 10 min read Pro lesson

Module 3: Node.js Internals: V8, libuv, the Event Loop

Node.js Internals: V8, libuv, the Event Loop — 8 topics.

• What Node.js Actually Is: The Anatomy of the Binary 11 min read Pro lesson
• V8: Google's JavaScript Engine 15 min read Pro lesson
• libuv: The C Library Underneath the Event Loop 12 min read Pro lesson
• The Event Loop: Phases in Detail 12 min read Pro lesson
• Microtasks, Macrotasks, process.nextTick 8 min read
• setTimeout vs setImmediate vs process.nextTick 8 min read Pro lesson
• The Threading Model: Single-Threaded User Code, Multi-Threaded Internals 9 min read Pro lesson
• Worker Threads: When JavaScript Itself Needs to Be Parallel 11 min read Pro lesson

Module 4: Modules & the Package Ecosystem

Modules & the Package Ecosystem — 7 topics.

• How `require` Actually Works: CommonJS Internals 9 min read Pro lesson
• How `import` Actually Works: ESM Internals 9 min read Pro lesson
• Interop: When CommonJS and ESM Coexist 8 min read Pro lesson
• The `package.json` Contract 7 min read Pro lesson
• npm, pnpm, and yarn: Choosing a Package Manager 6 min read Pro lesson
• Semver, Lockfiles, and Supply-Chain Safety 7 min read Pro lesson
• Native Modules and N-API: A Brief Tour 7 min read Pro lesson

Module 5: Building HTTP Servers from Scratch

Building HTTP Servers from Scratch — 5 topics.

• The Raw `http` Module: Building a Server With No Framework 8 min read Pro lesson
• Request and Response Lifecycle in Detail 9 min read Pro lesson
• Building Your Own Tiny Framework: Routing and Middleware 9 min read Pro lesson
• Express in Depth 9 min read Pro lesson
• Express vs Fastify vs Koa vs NestJS: Choosing a Framework 9 min read Pro lesson

Module 6: Core APIs: File System

Core APIs: File System — 5 topics.

• The fs Module: APIs and Tradeoffs 6 min read Pro lesson
• Reading and Writing Files 9 min read Pro lesson
• Working with Paths - the `path` Module 5 min read Pro lesson
• Directories and Metadata 7 min read Pro lesson
• File Watching: `fs.watch` and chokidar 5 min read Pro lesson

Module 7: Core APIs: Streams

Core APIs: Streams — 8 topics.

• The Streams Mental Model 7 min read
• Readable Streams in Detail 7 min read Pro lesson
• Writable Streams in Detail 6 min read Pro lesson
• Backpressure: The Core Problem Streams Solve 7 min read Pro lesson
• `pipe()` and `pipeline()` 5 min read Pro lesson
• Transform Streams and Stream Composition 6 min read Pro lesson
• Async Iterators on Streams 6 min read Pro lesson
• Production Patterns and Common Pitfalls 8 min read Pro lesson

Module 8: Core APIs: Network

Core APIs: Network — 5 topics.

• The `net` Module: TCP From Scratch 7 min read Pro lesson
• `dgram` - UDP 5 min read Pro lesson
• The DNS Module 6 min read Pro lesson
• HTTPS and TLS 7 min read Pro lesson
• HTTP/2 6 min read Pro lesson

Module 9: Building HTTP Servers, Continued

Building HTTP Servers, Continued — 5 topics.

• Streaming HTTP Responses 7 min read Pro lesson
• File Uploads in HTTP 7 min read Pro lesson
• Cookies, Sessions, and Authentication Concepts 8 min read Pro lesson
• CORS - the Actual Specification 8 min read Pro lesson
• Caching Headers and CDNs 8 min read Pro lesson

Module 10: Express.js and Web Frameworks

Express.js and Web Frameworks — 7 topics.

• Express: What It Is, What It Isn't 9 min read
• Routing in Express 6 min read Pro lesson
• Middleware in Express 7 min read Pro lesson
• Error Handling in Express 9 min read Pro lesson
• Templating and Rendering 6 min read Pro lesson
• Fastify, Koa, NestJS, Hapi - When to Pick Which 9 min read Pro lesson
• Building Production-Grade Express Apps 9 min read Pro lesson

Module 11: Working with Databases

Working with Databases — 8 topics.

• Connecting to a Database: the Driver Pattern 8 min read Pro lesson
• Connection Pooling: Why It Matters 10 min read Pro lesson
• PostgreSQL with `pg` 8 min read Pro lesson
• MySQL with `mysql2` 8 min read Pro lesson
• Prisma - ORM-Style With Type Safety 9 min read Pro lesson
• Drizzle, Knex, TypeORM - Alternatives 8 min read Pro lesson
• MongoDB with Mongoose 8 min read Pro lesson
• Redis: Caching and Beyond 10 min read Pro lesson

Module 12: Testing in Node.js

Testing in Node.js — 6 topics.

• The Testing Mindset: What to Test and Why 10 min read
• Node's Built-In Test Runner 8 min read Pro lesson
• Vitest, Jest, Mocha - The Alternatives 9 min read Pro lesson
• Mocking and Stubbing 10 min read Pro lesson
• Testing Async Code 10 min read Pro lesson
• Integration Testing with Real Databases 10 min read Pro lesson

Module 13: Debugging & Profiling

Debugging & Profiling — 6 topics.

• The Debugger: Inspector Protocol 9 min read Pro lesson
• Debugging Async Code 9 min read Pro lesson
• Memory Leaks: Finding and Fixing 11 min read Pro lesson
• CPU Profiling 10 min read Pro lesson
• Diagnostic Reports and Async Hooks 9 min read Pro lesson
• Debugging in Production Safely 10 min read Pro lesson

Module 14: Performance Engineering

Performance Engineering — 6 topics.

• Performance Mindset for Node 10 min read Pro lesson
• Common Node Bottlenecks 9 min read Pro lesson
• GC Tuning and Memory 8 min read Pro lesson
• Scaling: Cluster, Worker Threads, or Scale Out? 9 min read Pro lesson
• Caching Strategies 10 min read Pro lesson
• Database Query Optimization for Node Services 10 min read Pro lesson

Module 15: Error Handling & Logging

Error Handling & Logging — 5 topics.

• Error Handling Discipline 10 min read Pro lesson
• Promises, async/await, and Unhandled Rejection 9 min read Pro lesson
• Uncaught Exceptions and Crash Strategy 10 min read Pro lesson
• Structured Logging: Pino, Winston, and Patterns 9 min read Pro lesson
• Observability: Metrics, Traces, Logs Together 11 min read Pro lesson

Module 16: Security

Security — 6 topics.

• Input Validation: Zod, Joi, and the Principle 10 min read
• Authentication Patterns 12 min read Pro lesson
• OWASP Top 10 in Node 8 min read Pro lesson
• Helmet, Rate Limiting, CORS in Practice 8 min read Pro lesson
• Dependency Security: npm audit and Beyond 9 min read Pro lesson
• Secret Management 11 min read Pro lesson

Module 17: Building APIs

Building APIs — 7 topics.

• REST API Design Principles 12 min read Pro lesson
• REST in Express (or Fastify): Full Walkthrough 9 min read Pro lesson
• GraphQL with Apollo Server 11 min read Pro lesson
• gRPC in Node 8 min read
• API Versioning Strategies 11 min read Pro lesson
• OpenAPI / Swagger Documentation 8 min read Pro lesson
• Rate Limiting and Quota Strategies 10 min read Pro lesson

Module 18: Real-Time Applications

Real-Time Applications — 6 topics.

• The WebSocket Protocol: Actually Understanding It 10 min read Pro lesson
• The `ws` Library: Minimal and Direct 7 min read Pro lesson
• Socket.IO: When the Abstraction Earns Its Keep 9 min read Pro lesson
• Server-Sent Events and Long Polling 9 min read Pro lesson
• Scaling Real-Time: Redis Pub/Sub and Sticky Sessions 11 min read Pro lesson
• Real-Time Auth: Connection Lifecycle and Authorization 10 min read Pro lesson

Module 19: TypeScript in Node.js

TypeScript in Node.js — 6 topics.

• Why TypeScript for Node 9 min read
• tsconfig.json: The Field-by-Field Tour 9 min read Pro lesson
• Running TypeScript: tsc, ts-node, tsx, Native Node 10 min read Pro lesson
• Type-Safe APIs End-to-End 10 min read Pro lesson
• ESM + TypeScript: The Current State 10 min read Pro lesson
• Common TypeScript Patterns in Node Code 12 min read Pro lesson

Module 20: Deployment & Production

Deployment & Production — 6 topics.

• Process Management: PM2, systemd, and the Alternatives 10 min read Pro lesson
• Docker for Node.js 8 min read Pro lesson
• Configuration and Environment Variables 10 min read Pro lesson
• Graceful Shutdown 10 min read Pro lesson
• Health Checks and Readiness 10 min read Pro lesson
• CI/CD for Node Services 11 min read Pro lesson

Module 21: Microservices & Distributed Systems

Microservices & Distributed Systems — 6 topics.

• When Microservices Fit (And When They Don't) 10 min read Pro lesson
• Service Discovery and Inter-Service Communication 10 min read
• Message Queues: RabbitMQ, BullMQ, Kafka 10 min read Pro lesson
• Distributed Tracing 8 min read Pro lesson
• Resilience Patterns: Retry, Circuit Breaker, Bulkhead 11 min read Pro lesson
• Saga and Outbox Patterns 10 min read Pro lesson

Module 22: Node.js for Tooling

Node.js for Tooling — 5 topics.

• CLI Development: commander, yargs, clipanion 7 min read Pro lesson
• Interactive CLIs: inquirer, prompts 7 min read Pro lesson
• Build Tools Under the Hood: esbuild, Vite, swc 9 min read Pro lesson
• File Watchers and Dev Servers 8 min read Pro lesson
• Code Generators and Scaffolding 9 min read Pro lesson

Module 23: Advanced Patterns

Advanced Patterns — 5 topics.

• EventEmitter: The Pattern Under Everything 9 min read
• Async Iterators in Production 9 min read Pro lesson
• AbortController and Cancellation 10 min read Pro lesson
• AsyncLocalStorage and Async Context 11 min read Pro lesson
• Performance Hooks and Diagnostics Channels 10 min read Pro lesson

Module 24: The Node.js Ecosystem in 2026

The Node.js Ecosystem in 2026 — 4 topics.

• Deno: What It Is, What It Changed 8 min read Pro lesson
• Bun: Speed and Ambition 8 min read Pro lesson
• Edge Runtimes: Workers, Edge, Deno Deploy 9 min read Pro lesson
• The Future of Node 9 min read Pro lesson

Module 25: Node.js Interview Preparation

Node.js Interview Preparation — 5 topics.

• The Node.js Interview Landscape 10 min read Pro lesson
• Event Loop Questions: All of Them 9 min read Pro lesson
• System Design with Node in the Stack 11 min read Pro lesson
• Performance Debugging Stories: Interview-Ready 11 min read Pro lesson
• The Capstone Project 10 min read Pro lesson

Module 26: Capstone — Build a Link-in-Bio Service

Capstone — Build a Link-in-Bio Service — 6 topics.

• Project Setup: TypeScript, Fastify, Config 7 min read
• The Data Layer: Postgres, Migrations, Redis 10 min read Pro lesson
• Core API: Auth, Pages, Links, Public Reads 10 min read Pro lesson
• Background Worker and Async Processing 9 min read Pro lesson
• Production Hardening: Observability, Errors, Shutdown 9 min read Pro lesson
• Testing, Docker, CI 11 min read Pro lesson

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