🧵 Your React app is shipping MBs of useless JS

This Week's Sponsor Is… Well, Me!

Quick question: Have you ever finished a React tutorial, felt pretty good about it, and then immediately thought…

"Okay… so what do I learn next?"

And then spent 2 hours researching whether you should learn state management, or TypeScript, or routing, or hooks patterns, or… wait, what even IS the right order?

Yeah. That's the problem.

👉 Cosden Code isn't another random React course. It's a complete learning platform with a clear roadmap from beginner to advanced.

Here's what that actually means:

✅ Never wonder "what's next"
Clear, structured curriculum that builds logically. You always know exactly what to learn and when. No more analysis paralysis.
✅ Everything in one place
No more juggling 10 browser tabs. Video lessons, hands-on coding environment, AI mentor, and community, all unified in a single platform.
✅ Learn by building, not just watching
Every lesson includes interactive coding challenges. You write real React code and get instant feedback. This is how understanding actually sticks.

If React mastery is your 2026 goal, this is your complete roadmap:

👀 The next era of React has arrived: Here’s what you need to know
This article breaks down the new era of Async React, showing how React 19’s coordination primitives, like Actions, Suspense, use(), transitions, deferred values, and optimistic updates, finally eliminate the messy manual async handling we’ve all been hacking around for years. It explains how these tools work together to create UIs that stay responsive even on slow networks, why this shift matters for real-world apps, and how frameworks like Next.js are already baking these patterns in.

⚙ Controlled vs Uncontrolled Components in React
This article breaks down the classic controlled vs uncontrolled question in React by focusing on the real core: who owns the state, the parent or the component itself? It shows how this applies both to form inputs and custom components, why controlled patterns enable coordination between parts of your UI, and when uncontrolled patterns keep things simpler and more performant. You’ll walk away understanding how to design components that behave predictably, when to expose value/onChange-style APIs, and why mixing modes leads to bugs. Great read if you want to level up how your React components communicate.

🧠 TanStack AI - A powerful, open-source AI SDK
TanStack just dropped TanStack AI, a super clean, fully open-source AI SDK that gives you a unified, type-safe interface across OpenAI, Anthropic, Gemini, Ollama, and whatever else you plug in, no vendor lock-in, no proprietary wrappers, just pure TypeScript sanity. It standardizes tool calling, streaming, reasoning tokens, client/server adapters, and even ships with next-gen devtools so you can actually see what your AI stack is doing.

‼ Avoid These TanStack Router Mistakes
This post digs into the real-world “skeletons” you hit when building production apps with TanStack Router + Better Auth, and how to architect routes, layouts, guards, and loading states so your UI feels solid instead of spooky. Oscar walks through layout patterns that actually scale, the notorious auth flash bug and how to eliminate it with async guards, and the polish steps, pending components, error boundaries, validated search params, that turn a flexible router into a clean, predictable system.

🦥 Why Your React App Is Shipping Megabytes of Useless JavaScript
This guide walks you through a practical, detective-style approach to shrinking bloated JavaScript bundles, showing exactly how to analyze bundle graphs, spot oversized dependencies, fix broken tree-shaking, replace heavy libraries, and eliminate accidental duplicates. Nadia shows how a tiny app ballooned to 5MB of JS and then step-by-step trims it down to ~600KB using real examples with MUI, Lodash, Moment, Luxon, and transitive dependencies. If you’ve ever wondered why your React app feels heavier than it should, this article gives you a repeatable workflow for diagnosing and fixing bundle size issues.

Quick Links

⁉ CSS Wrapped 2025
This year’s CSS Wrapped 2025 is a full recap of how far things have developed this year, highlighting the features that quietly transformed front-end workflows across the year, from customizable selects and declarative dialog/popover controls to new carousel primitives, anchored container queries, scroll-state styling, sibling-index animations, view-transition upgrades, and ergonomic helpers like typed attr(), if().

💻 What Millions of AI Agent Queries Reveal About Developers
This Perplexity + Harvard study gives the first large-scale look at how people actually use AI agents in the real world, and the findings flip the usual “digital butler” narrative on its head. The data shows most usage is deep cognitive work, productivity, research, analysis, not errands or simple tasks, and heavy users evolve from casual queries into full workflow delegation over time.

💵 Has the cost of building software just dropped 90%?
This essay argues that agentic coding tools are collapsing the cost and time of building software, by something like 90% for many projects, shifting the bottleneck from typing code to thinking clearly about the problem and domain. Martin describes how small teams using AI agents can now ship in a week what used to take a month, with agents handling boilerplate, tests, and refactors while humans provide architecture and domain judgment. Instead of killing demand for developers, this unleashes huge latent demand for custom software, making domain expertise and the ability to steer agents the real moat.

🤔 A Better Way for Engineers to Stay Motivated on Long-Term Goals
This guide digs into why engineers’ long-term goals usually collapse and shows how mixing SMART top-down goals with tiny bottom up experiments creates motivation that actually survives chaos. Fran breaks down the motivation equation, expectancy, value, impulsiveness, delay, and explains how big goals fail because the rewards are too far away and work is too unpredictable.