Svelte 5 signals fix its glitchy and inconsistent reactivity

I wrote this blog post about how Svelte 5 (currently a release candidate) uses signals to fix two problems with its former reactivity system that was introduced 5 years ago.

If you were unaware, signals are being adopted by almost every major frontend framework except React. From the TC39 proposal[1] to add them to the JS language - "Angular, Bubble, Ember, FAST, MobX, Preact, Qwik, RxJS, Solid, Starbeam, Svelte, Vue, Wiz". Adding signals to JS would enable standardized developer tooling around them among other benefits, the proposal describes more.

Signals also enable Svelte 5's fine-grained reactivity, which again puts it among the performance benchmark leaders, and the signals DX with runes[2] is simply fantastic in my experience.

[1] https://github.com/tc39/proposal-signals

[2] https://svelte.dev/blog/runes

There's also a video if you'd prefer to watch - https://www.youtube.com/watch?v=lcnimZTNOCA

Nobody wants another breaking change. Svelte totally lost it