Reactivity in Frontend: Thinking in Signals

Every modern frontend framework promises the same thing: change your data, and the UI updates automatically. But how they deliver on that promise varies wildly. From React's Virtual DOM diffing to Vue's proxy-based dependency tracking to Solid's direct DOM subscriptions.

This talk traces the full arc of frontend reactivity: starting with Angular's dirty checking in 2010, through React's VDOM, Vue's Composition API, Svelte's compiler-powered runes, and Solid's fine-grained signals. It breaks down the core pattern that underpins all of them: a dependency class with track and trigger.

Along the way, we compare how Vue, Solid, Angular, Svelte 5, Preact, and Qwik each implement the same three primitives (signal, computed, effect), and explain why the industry is converging on a single reactive model.