VanJS is impressively tiny - just 1KB of runtime with zero dependencies. It's basically "what if we took the reactive parts of modern frameworks and stripped away everything else?" The result is surprisingly elegant for simple applications, but you'll quickly bump into its limitations.

The functional approach is refreshing after dealing with classes and complex component lifecycles. van.state(initialValue) creates reactive state, van.tags.div() creates DOM elements, and everything just works. Our weather app's temperature display is literally van.tags.span(temperature) - when temperature changes, the DOM updates automatically.

But the simplicity comes with trade-offs. There's no component abstraction beyond functions, no templating system, no event system. You're essentially building a reactive version of vanilla DOM manipulation. It works for basic interactivity but gets unwieldy fast.

The DOM creation syntax is functional but verbose: van.tags.div({class: "weather-card"}, van.tags.h2("Weather")). Coming from JSX or template languages, it feels like writing assembly code. You'll miss the declarative nature of modern frameworks.

VanJS works well for simple enhancements where you need just a touch of reactivity without the framework overhead. I've used it for mini apps, like raid-calculator. But for anything substantial, you'll spend more time fighting the limitations than building features. It's an interesting experiment in minimalism, but modern frameworks exist for good reasons.