Modern JavaScript Tooling in 2026

Node.js, Bun, pnpm, Vite, TypeScript, Biome, Vitest & Beyond

Introduction: The State of JavaScript Tooling in 2026

Chapter 1: Foundations (Modules, Runtimes, and the Modern Landscape)

1. The Module Problem: From Globals to ESM
2. CommonJS vs ES Modules: Mechanics, Interop, and When It Matters
3. How JavaScript Runs: V8, Sandboxing, and Runtime Architecture
4. The Node.js Legacy: Why It Dominated and What It Left Behind
5. Modern Alternatives: Bun, Deno, and the New Competition
6. Choosing Your Runtime: Decision Framework for 2026

Chapter 2: Package Management (npm, pnpm, Corepack, and the Dependency Model)

1. The package.json Contract: Fields, Scripts, and Modern Conventions
2. How npm Works: Registry, Resolution, Lock Files, and Installation
3. pnpm: Content Addressable Storage, Symlinks, and Disk Efficiency
4. Corepack: Version Pinning Without nvm or fnm
5. Monorepos and Workspaces: npm, pnpm, and Turborepo Integration
6. Dependency Hygiene: Auditing, Updating, and Security Scanning

Chapter 3: TypeScript (The Type System That Changed Everything)

1. Why TypeScript Won: Adoption, Tooling, and Developer Experience
2. tsconfig.json Mastery: Strict Mode, Paths, and Project References
3. Type System Fundamentals: Inference, Generics, and Utility Types
4. TypeScript with Node.js: Runtime vs Type-Only Concerns
5. TypeScript in the Browser: Bundling, Transpilation, and Distribution
6. Migration Strategies: Adding Types to Legacy JavaScript Codebases

Chapter 4: Transpilation and Compilation (tsc, SWC, esbuild, Babel)

1. What Transpilation Solves: Targeting Environments That Do Not Exist Yet
2. TypeScript Compiler (tsc): Capabilities, Limitations, When to Use It
3. esbuild: Go-Based Speed and the Bundler/Transpiler Blur
4. SWC: Rust-Powered Compilation for Maximum Performance
5. Babel’s Evolving Role: Plugins, Presets, and Legacy Support
6. Choosing Your Transpiler: A Decision Matrix

Chapter 5: Bundling (Vite, Rollup, esbuild, and the Modern Build Pipeline)

1. Why We Bundle: Modules, HTTP, and Browser Constraints
2. Vite Deep Dive: Dev Server, Build Mode, Plugins, and Configuration
3. Rollup: Library Bundling, Tree Shaking, and the ESM Standard
4. esbuild as a Bundler: Speed Versus Flexibility
5. Webpack’s Remaining Role: When It Still Makes Sense in 2026
6. Bundle Analysis: Measuring Size, Dependencies, and Performance Impact

Chapter 6: Linting, Formatting, and Code Quality (Biome, ESLint, Prettier)

1. The Code Quality Stack: Why Formatting and Linting Are Separate Concerns
2. Biome: The Rising All-in-One Alternative to ESLint + Prettier
3. ESLint in 2026: Flat Config, Plugins, and Continued Dominance
4. Prettier: Opinionated Formatting and the End of Style Debates
5. Type Checking as Linting: Integrating TypeScript into Your CI
6. Designing a Code Quality Pipeline: Fast Local Feedback, Strict CI Gates

Chapter 7: Testing (Vitest, Jest, Playwright, and the Testing Pyramid)

1. The Testing Pyramid for JavaScript Applications
2. Vitest: Vite-Native Unit Testing with esbuild Speed
3. Jest in 2026: Legacy Strengths and When It Still Belongs
4. Playwright: Cross-Browser E2E Testing and Component Testing
5. Mocking Strategies: Modules, APIs, and External Dependencies
6. Test Configuration for Production Workflows: Coverage, CI, and Flaky Tests

Chapter 8: Debugging, Profiling, and Developer Experience

1. Source Maps: How They Work and Why They Are Essential
2. Debugger Tools: Chrome DevTools, VS Code, and Node.js Debugging
3. Profiling Performance: CPU, Memory, and Startup Time Analysis
4. Error Tracking in Production: Sentry, LogRocket, and Observability
5. Logging Strategies: From console.log to Structured JSON Logs
6. DX Optimization: Fast Feedback Loops and Hot Module Replacement

Chapter 9: Building for Distribution (Libraries, CLIs, and npm Publishing)

1. Package Design: API Surface, SemVer, and Breaking Changes
2. Dual ESM/CommonJS Exports: The export Field Map Strategy
3. TypeScript Declaration Files: Publishing Types with Your Library
4. CLI Applications: Shebangs, Bin Fields, and Cross-Platform Execution
5. Publishing to npm: Tokens, Access Control, and Release Automation
6. Versioning Strategies: Changesets, Conventional Commits, and CalVer

Chapter 10: Frontend Development Workflows (Frameworks, SSR, and the Vite Ecosystem)

1. Vite as the Universal Frontend Toolchain
2. React in 2026: Server Components, Streaming, and Build Integration
3. Next.js App Router: SSR, ISR, Edge Functions, and Bundling
4. SvelteKit and Astro: Alternative Architectures
5. CSS Tooling: Tailwind, PostCSS, and Modern Styling Approaches
6. Asset Handling: Images, Fonts, and Content Delivery

Chapter 11: Backend Development (Node.js, Bun, and Server-Side JavaScript)

1. Express in 2026: Still Relevant or Time to Move On?
2. Fastify, Hono, and Elysia: High-Performance Alternatives
3. Database Integration: Prisma, Drizzle, and Type-Safe Queries
4. API Design: REST, GraphQL, tRPC, and OpenAPI
5. Authentication and Authorization in Modern JavaScript Apps
6. WebSockets, Server-Sent Events, and Real-Time Communication

Chapter 12: CI/CD, Containers, and Deployment

1. Continuous Integration for JavaScript: GitHub Actions, GitLab CI, and Build Caching
2. Dependency Caching Strategies Across CI Providers
3. Containerizing Node.js Applications: Multi-Stage Builds and Minimal Images
4. Serverless Deployment: Vercel, Netlify, Cloudflare Workers, AWS Lambda
5. Deploying to Containers: Docker Compose, Kubernetes, and Orchestration
6. Monitoring and Alerting: Health Checks, Metrics, and Uptime

Chapter 13: Security (Dependencies, Runtime, and Supply Chain)

1. The Dependency Vulnerability Problem: npm Ecosystem Risks
2. Scanning Tools: npm audit, Snyk, Dependabot, and Renovate
3. Supply Chain Attacks: Typosquatting, Compromised Packages, and Mitigation
4. Hardening Node.js Applications in Production
5. Secrets Management: Environment Variables, Vault Integration, and Runtime Safety
6. Content Security Policy and Browser-Side Security

Chapter 14: End-to-End Projects (Complete Workflows for Real-World Development)

1. Project 1: A Production TypeScript Library with CI, Testing, and Automated Publishing
2. Project 2: Full-Stack Vite + Node.js Application with Database Integration
3. Project 3: A Monorepo with Turborepo, pnpm Workspaces, Changesets, and Shared Configuration
4. Migration Case Study: Moving from Create React App to Vite with Modern Tooling

Conclusion (Building With Confidence in a Fast-Moving Ecosystem)

References