Custom API Developer — QR Code, SMS, and Shopify Integration

We are looking for an experienced API developer to create a backend system that handles user registration, QR code generation, points tracking, and automated SMS messaging, with integration to a Shopify store.

Project Scope:
User Registration & QR Generation:
Generate a unique QR code for each user upon registration.
QR codes can be scanned by other users to award points.

Points System:
Track user levels and points automatically.
Support variable points based on user or QR code level.

SMS Integration:
Automatically send SMS for account confirmation, QR delivery, and points updates.
Preferably using Twilio, MessageBird, or similar services.

Shopify Integration:
Sync user accounts and points with Shopify for product rewards or level unlocks.

Requirements:
Strong experience in API development (REST or GraphQL)
Experience with QR code generation and tracking
Experience with SMS API integration
Experience with Shopify API is a plus
Ability to provide documentation for future updates

Deliverables:
Fully functional API ready for integration
Documentation for deployment and maintenance
Example endpoints for QR generation, points tracking, and SMS