Cognitive stress has always been a challenge when dealing with new languages, features and APIs. Oftentimes, we find ourselves experimenting with new features, rather than only reading their documentation. Either with a debugger, a REPL environment, or a thousand console.logs, we explore what these tools do. But what if there was something that will further cut the time between writing code and seeing the result? JS Eval is a tool that achieves exactly this by displaying the evaluation results of your program directly where they come from. Join me as we dive into its plethora of features and how they can help you understand the new tools you encounter!

In this talk, I'll uncover some tricks and hacks in React that I learned while maintaining a micro-library (2KB Router). We'll discuss performance and size optimizations, as well as the importance of keeping object references stable when passing them down as props to React components.

I'd like to cover the non-standard use of the useState hook, cloneElement API for component composition, the useSyncExternalStore hook introduced in React 18, and its caveats; as well as lesser-known non-standard hooks such as useEvent and more. To demonstrate these tricks, we'll built a fake multiplayer client component.

Let's be honest, nowadays most of us see an error, copy it into ChatGPT, and hope for the best. I've done it. You've done it. We've all wasted 30 minutes going back and forth with AI when our browser could've shown us the answer in 2 minutes.

This talk is about remembering that our browsers have incredible debugging tools we've forgotten how to use. Through live demos of real bugs, I'll show you how breakpoints, call stacks, and the network tab can solve problems maybe faster than any AI assistant.

You'll learn:

• How to ditch console.log hell and actually watch your code run
• Breakpoint tricks that pause your app so you can inspect what's really happening
• How to read call stacks without your eyes glazing over
• Network tab techniques that expose exactly why your API is misbehaving
• When debugging tools beat AI (and when AI is actually helpful)
 I'm not saying don't use AI—I use it all the time. But there's something powerful about understanding your own code well enough to fix it yourself. Plus, you'll be way faster, and you'll actually learn something instead of just copy-pasting solutions you don't understand.

A hands-on session working through pernicious React bugs, and how to squash them for good. By working through a concrete Todo List example, we’ll leverage TypeScript and JavaScript features to gradually improve the reliability and performance of our code. We might even push beyond the limit of what’s sensible, inviting a reflexion on the balance of code readability and its runtime performance.