AlexWebLab

Explore a wide range of web development topics, from JavaScript to React and beyond, and uncover valuable insights to enhance your skills.

Latest 2 articles:

IntersectionObserver Internals: How the Browser Detects Visibility

Browser Internals

IntersectionObserver is the standard API for detecting when an element enters or leaves the viewport. Understanding how it works under the hood — and what its limitations are — helps you use it efficiently and avoid the subtle bugs that come from misunderstanding when callbacks fire.

Hydration in React: What It Is and Why It Sometimes Goes Wrong

Rendering & Frameworks

Hydration is the process of attaching React's event listeners and state to server-rendered HTML. It's what makes SSR-rendered pages interactive — and when it fails, you get one of the most confusing categories of React error.