SvelteKit[1] is a framework for SvelteJS (like Next.js is a framework for ReactJS). I've tried both Svelte and React. Svelte seems to be more elegant and lets me implement my ideas faster with less code. Svelte is very flexible; SvelteKit adds some opinions on how to do things like routing.
SvelteKit also embraces the serverless paradigm[2] (AKA JAMstack[3]). Although a node.js server is still an option, you can also have pages rendered in serverless functions or pre-rendered at build time. Even static pages can be "hydrated" on the client so they are not totally static. So this results in fine-grained SSR (server-side rendering) at the page level. The two main reasons for SSR are performance (especially on mobile devices) and SEO.
Backendless[4] is a VADP/MBaaS. This platform offers a lot of services, but the main one I'm looking at is authentication/identity. I was looking for an authentication service that supports anonymous guest login, social login, as well as traditional email/password login. The other contenders were Google Firebase (slow, and confusing sign in/sign up flow[5]) and AWS Cognito (too complicated/difficult to use). Auth0 was a contender, but they don't support guest logins.
[2]: https://www.serverless.com
[3]: https://jamstack.org