CDCooldecode
Cooldecode
A personal learning blog for frontend, backend, tooling and AI — one post at a time.
Every post has its own EN/PT toggle inside — pick a language once you open it.
Learn what AI is creating for you. Don't get lost.
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Week 1 · Lesson 107/26/2026
How the web works today
Client, server, build tools — and where each piece of the "modern stack" fits in.
Week 1 · Lesson 207/26/2026
Frontend vs Backend
The big picture: what runs where, and why.
Week 1 · Lesson 307/27/2026
Plain HTML/CSS/JS vs frameworks
When the extra complexity of a framework pays off — and when it doesn't.
Week 1 · Extra07/26/2026
Module 1 — extra material
Follow-up questions and deeper dives from week 1: SEO & rendering, Django/Rails, JSX, build tools.
Week 2 · Lesson 407/28/2026
Introduction to React
Components, JSX, props and state — the mental model behind React.
Week 2 · Lesson 507/29/2026
React hooks: useState, useEffect
What each hook solves, compared with doing it by hand in plain JS.
Week 2 · Lesson 607/30/2026
What Next.js is
Why almost nobody ships plain React in production, and what Next.js adds.
Week 2 · Lesson 708/03/2026
App Router: Server vs Client Components
Every component starts as a Server Component by default — what that means and when to opt into a Client Component.
Week 2 · Lesson 808/04/2026
Static vs SSR vs SSG vs ISR
Four moments the HTML can be built — and how to pick the right one for each page.
Week 2 · Lesson 908/05/2026
Why use Vercel
Native Next.js integration, preview URLs, edge functions — and the honest downsides, including the metered bill.
AI Watch07/26/2026
Claude Opus 5
What changes in Anthropic's new top-tier model.
AI Watch07/27/2026
Context window
What it is, and why 1M tokens doesn't fix everything.
AI Watch07/28/2026
Prompt engineering in practice
What changed in 2026 with reasoning models, and what fell out of favor.
AI Watch07/29/2026
MCP's new spec
Model Context Protocol goes stateless — what changes and why.
AI Watch07/30/2026
Industry landscape
GPT-5.6 ships, Gemini 3.5 Pro gets delayed — mapping the July 2026 race.
AI Watch08/03/2026
Cowork goes mobile and web
Anthropic expands Cowork beyond desktop, with sessions that now run remotely and keep going with no device online.
AI Watch08/04/2026
Embeddings, explained
How meaning becomes math — the concept behind semantic search and RAG.
AI Watch08/05/2026
Model lifecycles, deprecation and pricing
Claude Opus 4.1 retires today and Sonnet 5's intro pricing ends Aug 31 — why model IDs are perishable infrastructure.
Deep dive07/26/2026
Tailwind CSS
Utility-first, JIT, design tokens, comparisons and when to use it.
Deep dive07/26/2026
Next.js + React
What each one is, how they work, when to use them and when not to.
Deep dive08/02/2026
Frameworks & deploy presets
Every framework in Vercel's import dropdown, grouped by what it actually solves.
More posts coming soon: Git & GitHub, other databases, AWS, more languages to watch, API integration.