🧑‍💻 Cosden Code Waitlist
A new kind of platform where expert-crafted React courses meet intelligent, AI-powered guidance. Human-designed, AI-delivered. The waitlist is now open, and I will be selecting people to beta test shortly!

🆕 Next.js 15.5 Releases
Next.js 15.5 is here, bringing a wave of developer experience upgrades. Expect Turbopack stability improvements, smoother error handling in the App Router, and PostCSS plugin support, finally added to Turbopack. Also bundled in: TypeScript 5.5 support and a new metadataTimeout config to help with slow dynamic metadata.

🗄 Has anyone tried TanStack DB yet? Looking for early impressions
We recently shared TanStack DB in this newsletter, here’s some honest early feedback from Reddit. Devs are liking the declarative, TypeScript-first approach, but a few are holding off due to limited docs and the fact that it’s still early-stage. It’s promising, but most agree it’s not quite prod-ready yet

🤔 Why do we need Context/Redux/Zustand in React
This piece breaks down where useState shines, local, component-level state, and where it starts to struggle, especially with global or persistent state that needs to survive page reloads. It walks through when to reach for localStorage (like themes or auth) instead of Context, and also touches on libraries like Zustand and Jotai as cleaner alternatives for shared state without the boilerplate.

💼 React Mock Interview (video)
In this mock interview episode, Kent C. Dodds, Jack Herrington, and Piyush Agarwal go head-to-head in a timed React challenge. You’ll see how top engineers approach problems under pressure, think out loud, and structure their solutions, plus get practical tips for your own interview prep. A rare peek into real-time problem solving from seasoned devs.

🖼 What Learning React Won't Teach You: Image Formats
React doesn’t really care what image format you use, but your users, performance, and Core Web Vitals definitely do. This post breaks down why sticking with old formats like JPEG or PNG can hurt load times, especially on mobile, and explores how modern formats like WebP and AVIF can drastically reduce file size without losing quality. It also shows how to serve different formats using the <picture> tag and touches on how build tools can automate this.

🔐 The State of MCP Security
Pynt's latest post breaks down why MCPs, connectors between AI agents and real, world tools, are becoming a major security blind spot. When these systems combine, they can unintentionally expose hidden attack surfaces, even if each piece looks safe in isolation.

🆓 Free, open-source desktop companion for Claude Code
Claudia Code is a free, open-source desktop app that adds a slick GUI on top of the Claude Code CLI tool, turning AI coding sessions into a visual experience. You can manage agents, track API usage, navigate sessions with checkpoints, and work across Windows, macOS, or Linux, all from a central dashboard.

🧙 Svelte, Markdown, and the Magic of Web Components
This post explores how Svelte and Web Components can work together to bring dynamic interactivity to otherwise static Markdown content. By compiling Svelte components into custom elements, you can drop them straight into blog posts or docs, no client-side JS framework needed. It’s a really cool way to level up Markdown without sacrificing performance.

🧠 Sam Altman on GPT-6: ‘People want memory’
In an interview with CNBC, Sam Altman confirmed that memory is a central focus for GPT-6, with growing demand for AI that can recall past interactions and build more personalized, context-aware experiences. He said that while model quality still matters, users increasingly care about continuity and long-term usefulness, not just raw intelligence.

Quick Links

In this video, I'm going to share with you one of the biggest data fetching mistakes that juniors make in React. That mistake is not using React Query.

No matter how small your React application is or what type of application you have, you should always be using React Query and it should be your default.

Let me show you why!