MVP Platform Development for Business Tools

MVP Build — Quote Request

We're looking for a freelance developer or small team to quote an initial MVP build. This is a rough-scope request to get a ballpark quote — not a full technical spec. Additional phases/tiers will be scoped separately once we're underway.

What we're building (high level)

A web platform that connects to third-party business software a client already uses (accounting/ERP-type systems, CRM/marketing platforms, etc.), pulls their data into a secure cloud environment, and gives the client a simple portal to log in and view/query that data — including an AI-assisted question-answering feature over their own data.

Core skills required
Backend development (Node.js/Express or equivalent) — building and hardening API routes, working with an existing partially-built codebase
Cloud infrastructure automation (AWS) — Infrastructure-as-Code experience (CloudFormation, Terraform, CDK, or similar) to automate spinning up isolated, per-client cloud environments (compute/database instance, scoped access controls, networking) without manual console work
OAuth / third-party API integrations — connecting to external SaaS platforms (accounting, CRM/marketing tools) via their official OAuth flows and REST APIs; handling token storage securely
Database design — relational schema design (Postgres) for multi-tenant data with strict data-lineage/audit requirements
Authentication & access control — building secure login systems, including scoped per-client accounts (not just a single shared password)
AI/LLM API integration — wiring an LLM API (e.g. Anthropic/OpenAI) into a backend so it can answer natural-language questions against structured data, with usage logging
Security-conscious development — credential handling, secrets management, and client data isolation are hard requirements, not nice-to-haves
User interfaces needed (MVP scope)
Client onboarding flow — a guided, non-technical-friendly flow where a business user connects their existing tools (one at a time, via "Connect" buttons using OAuth — no manual API key entry) and sees live progress as their data syncs in
Client dashboard — a simple, clean view showing connected systems and basic status/health
Client login portal — each client gets their own secure, scoped account (not shared credentials)
AI query interface — a simple chat-style screen where the client can ask plain-English questions about their own data and get answers
Internal admin console — a basic internal tool for us to view/manage client accounts and monitor system status (already have a rough front-end shell for this; needs to be wired to a real database)
What's already in place
A partially built front-end and back-end scaffold (not production-ready)
Cloud hosting and one shared database instance (currently used for testing only)
One or two working example integrations to a third-party tool
What we need quoted

A quote for the initial MVP only, covering:

Hardening/completing the existing scaffold
Basic secure authentication (client + admin)
Automated, isolated per-client cloud environment provisioning
One or two working end-to-end integrations (data sync working reliably, not just proof-of-concept)
The client onboarding flow + dashboard + AI query interface (functional, not polished/final design)
Basic admin console wired to real data

We're not looking for a full build-out of every future integration or feature tier — just a working, reliable MVP we can trial with a small number of real clients before scoping further phases.

Please quote based on your best estimate of effort/time for the above. Happy to answer scoping questions before you finalize a number.