Topics

Check out the topics that interest you.

Fundamentals

Types, coercion, scope, closures, prototypes and the event loop: the parts of the language every bug eventually comes back to.

Arrow functions, this, currying, composition, generators and the functional habits that make JavaScript code small and testable.

Callbacks, promises, async/await, streams and cancellation, and how to keep concurrent code from racing itself.

Design patterns, OOP and classes, dependency injection, SOLID, DRY and clean architecture, written for how JavaScript actually works.

The runtime on the server: modules, the file system, HTTP, streams, workers, child processes and the APIs that replace half of npm.

Types that catch real bugs: generics, narrowing, utility and conditional types, tsconfig, and typing the libraries you already use.

The DOM, events, fetch, storage, workers and the Web APIs that ship in every browser, used without reaching for a framework.

Vitest, Jest, node:test and Playwright, plus mocks, fixtures and the testing habits that keep a suite fast and trusted.

React, Vue, Svelte, Angular, Next.js, Express, Fastify and NestJS: what each one does for you and what it quietly costs.

REST, GraphQL, WebSockets and webhooks from both ends: designing, validating, consuming and versioning APIs in JavaScript.

Profiling, memory leaks, V8 internals, bundle size and Core Web Vitals. Measure first, then make it fast.

XSS, prototype pollution, supply-chain attacks, secrets and auth: the holes attackers look for in JavaScript apps, and how to close them.

Bundlers, compilers, linters, formatters, monorepos and CI: Vite, esbuild, ESLint, Biome and the config that holds them together.

npm, pnpm and package.json in depth, and building your own library: ESM and CommonJS, exports maps, types, versioning and publishing.

DevTools, the Node inspector, source maps and stack traces: find the bug instead of the symptom, in the browser and on the server.