Modern Frontend & Scalable Backend Integration

I'm looking for a developer to create a modern and flashy frontend and integrate it with a scalable backend. The frontend should include user authentication and payment processing functionalities.

Key Requirements:
- Frontend Development:
- Modern and flashy design
- Integrate user authentication
- Integrate payment processing

- Backend Development:
- Scalable architecture
- Backend API calls to OpenAI

Ideal Skills & Experience:
- Proficiency in modern frontend frameworks (React, Vue.js, etc.)
- Experience with backend development and API integration
- Strong understanding of user authentication and payment processing
- Knowledge of OpenAI API is a plus
- Experience in building scalable systems

Please provide examples of previous work and relevant experience. Looking forward to your bids!