Cashback Management Web Application Development

I need a WEB application (NOT a mobile app) for a cashback management platform called “Interscambio”.

Important clarifications:

This is a WEB platform only

It must be responsive, but NOT a mobile app

There are NO in-app payments

The system does NOT handle money transfers

It only calculates and tracks cashback values

Cashback payouts are managed externally and only recorded in the system

Because of this, I expect:

Reasonable development cost

Fast delivery timeline

Project Overview:

The platform manages a cashback ecosystem involving:

Clients

Companies

Sales Advisors

Admin (with MFA login)

Main features:

• User registration with different roles
• Admin approval workflow (records move from “Pending” to “Approved”)
• Barcode-style unique IDs generation (C******, A******, S******)
• B2B and B2C transaction registration
• Automatic percentage calculation based on configurable rules
• Full transaction tracking and history
• Cashback tracking (calculated only, not paid inside the system)
• Admin validation of transactions
• Accounting summary views
• Invoice record management (manual entry by admin)
• Excel export functions
• Email notifications (SMTP config file required)

Technical requirements:

Web application only (no mobile app development)

PostgreSQL database

HTTPS / SSL

Role-based access

Full audit trail on edits

Logical deletion (no physical deletes)

Google Maps integration for company search

Online contract signature integration (DocuSign or similar)

There is NO:

Payment gateway integration

Financial transaction processing

Wallet system

Automatic payout logic

This is a structured data management platform with calculation logic and admin validation.

The full functional analysis document is attached (very detailed specification).

Please provide:

Estimated total cost

Estimated delivery time

Suggested tech stack

Confirmation you understand this is WEB only and no payment processing is required

I am looking for a developer or small team with strong backend logic skills.