Seeking Advice: Next.js vs Vite for HR SaaS (10K+ Users)

Hi Dev Community! 👋

I’m a developer currently building an HR SaaS platform. Our target is to support 10,000+ users and deliver robust features like employee dashboards, attendance systems, and public job postings. My primary goal is a solution that scales well(as job pages and company profiles need to be easily discoverable on Google).

My Dilemma: Next.js or Vite (with React)?
Here’s what I’ve researched and tested:

Next.js

1. Full-stack framework (API, SSR, SSG, routing all included)
2. SEO just works out of the box (SSR/ISR)
3. Proven at scale (10K+ users)
4. Everything integrated, but slower builds/higher server costs

Vite

1. Lightning-fast dev/build experience (but mainly SPA)
2. Needs separate backend setup
3. SEO is tricky; requires extra tools/config (not SSR by default)
4. Lower hosting costs and easier for small projects

Questions for the Dev Community:

1. Can Vite+React be made truly SEO-friendly (SSR, SSG, easy setup) for jobs/careers pages? Any practical solutions or success stories?
2. How would you architect scaling for 10K+ users with Vite, especially with real-time dashboards, notifications, and multi-tenant features?
3. Are there hidden challenges with Next.js at this scale, especially for fast deployments, costs, or developer productivity?
4. Is there a third approach I should consider? (e.g. Astro, Remix, Qwik, or something else)
5. Any tips or stories from experience running SaaS apps at similar scale?

Hosting: AWS Amplify Gen2