I haven't posted about the methodology yet but intend to. If you're interested in my initial impressions I made a video about it:
https://youtu.be/SIwKKgkjlbU
There's about a 99% chance you can update from Svelte 3 to 4 without any code changes. Some code changes are performed automatically by the migration script: https://svelte.dev/docs/v4-migration-guide
Great post, I came to much the same conclusion when building my app - a secure token is generated on account creation and users are encouraged to save it in case the need to restore their account. I blogged about the implementation below together with how the UI looks (under the "Authentication" heading):
https://khromov.se/building-a-privacy-friendly-self-hosted-a...
WordPress is very fast out of the box considering all its capabilities, it's not hard to get in the range of 100ms TTFB out of the box on dirt cheap VPS servers, which is pretty good in my book. The problem is that people add very heavy themes and plugins that push them well above acceptable TTFB numbers.
Full Site Editing with the new Gutenberg editor have amended a lot of that, it's very performant out of the box. Just as an example, I have a site averaging about 200ms for uncached requests, it has an FSE theme and 20 installed plugins, including heavy ones like ACF.
This is all out of the box without cache, but by adding a simple static page cache (either a plugin or something like Fastly, Varnish etc.) you can make it so that the p95 latency drops by 80-90% because most people will see cached page views any way.
It sounds like you have a misunderstanding about SvelteKit. It does have a client side router and you can use SvelteKit as a pure SPA today very easily, all you need is to set `export const ssr = false;` and `export const prerender = false;` in `src/routes/+layout.ts`. Then export with `adapter-static` and you're done.
I'm aware of that in fact, it's still far from the "pure" SPA as what React or Vue provides. SSR-first sveltekit is not the same as "pure" CSR SPA, and I do not need read all the SSR oriented doc to figure out how to do a CSR SPA. I spent a few months with Svelte(kit) and eventually returned to React.
If ever Svelte does CSR-first SPA with client side builtin router, I will definitely give a second try, until then, React will be my choice.
You would be hard pressed to find a functional difference between a SvelteKit project compiled with adapter-static and a "Create React App" app. If you have any concrete differences, do share them. They're functionally equivalent (except a SvelteKit project is a lot lighter in JS due to the compiler architecture).
There are unfortunately a lot of misunderstandings around SvelteKit because it is SSR-centric. SvelteKit has probably the best interactive docs of any framework at https://learn.svelte.dev/ and I do encourage everyone to go through them to get the full picture!
I tested the beta version of Svelte 4 on my app and it worked without requiring any changes other than running the migration script. Excellent work from the team!
