Step-by-step guides with working code. Ship something by the end.
Three wired GitHub Actions workflows for test, build, deploy. The caching pattern that halves CI time, plus 5 YAML traps that break teams.
React Compiler is stable in React 19. 3 memoization habits to delete, 2 cases where you still need useMemo, and the eslint plugin to run first.
TypeScript types vanish at runtime. Here are three boundaries — APIs, forms, config — where they fail, and Zod patterns that fix them.
Three copy-paste configs for your eslint flat config migration — React+Vite, Node API, monorepo — plus the CI-breaking pattern no one warns you about.
Three Node.js stream patterns — file transform, HTTP proxy, CSV parser — that process GBs in ~40MB of RAM, with heap proofs and the pipeline() trap explained.
Three before/after refactors showing how CSS light-dark() deletes duplicated :root variables, prefers-color-scheme blocks, and theme toggle hacks.
node:test is stable in Node 22+. Three server-side patterns — describe/it, built-in mocking, and coverage — that replace Jest for API code.
JavaScript iterator helpers let you .map() and .filter() lazily — no intermediate arrays. Three refactors you can ship this week, and one to skip.
Three API rate limiting strategies with real Express + Redis code: fixed window, sliding window, token bucket. Plus a decision rule for picking right.
These javascript fetch api patterns go beyond response.json(). Streaming, AbortController, and retry with backoff turn fetch into a real HTTP client.