Secure SaaS Conversion for Edu Tools

I already have two browser-based educational tools written in pure HTML + JavaScript. Your task is to lift them into a full SaaS product that students and teachers can subscribe to online.

Current assets
• Front-end code for both tools is clean and self-contained.
• No server side, no database yet.

Scope of work
1. Build a solid backend (language/framework of your choice) with a well-structured database and REST/GraphQL endpoints to serve both tools.
2. Implement account creation, email-verified login, password reset and session handling. The custom dashboard must include user management so I can create, edit, suspend and delete users from an admin view.
3. Integrate a production-ready payment gateway and wire it to tiered subscription plans (monthly / yearly). I’ll supply the plan details; you handle webhooks and fail-safe billing logic.
4. Harden the whole stack: OWASP-aligned code practices, rate limiting, input sanitisation, encrypted secrets, HTTPS everywhere.
5. Containerise or otherwise script deployment so I can spin up staging and production with minimal effort.
6. Hand over clear documentation and a short walkthrough video when done.

Acceptance criteria
• A new user can sign up, pay, log in and immediately access the tools.
• The admin panel shows real-time user status and lets me manage accounts without touching the database.
• Source code passes a quick security audit and all endpoints return 2xx/4xx/5xx as expected in a small test suite.
• Everything runs smoothly on a standard cloud VM.

Send me your proposed tech stack, timeline and any past SaaS examples you’ve built that highlight secure coding and smooth user management.