dev.to/smtahosin/svelte-5-isnt-pure-compiler-magic-how-runes-fine-grained-signals-and-direct-dom-mutations-36a3 Svelte 5 Isn't Pure Compiler Magic: How Runes, Fine-Grained Signals, and Direct DOM Mutations Actually Work Under the Hood
Svelte 5 replaces Svelte 4's compile-time assignment rewriting with Runes built on a push-pull signal graph, so reactive state can live outside .svelte files. Its compiler still hoists static templates into one cloned string and binds targeted effects that write directly to DOM nodes, avoiding virtual DOM diffing.
