Web-Based Application Design

I'm looking for a skilled and experienced developer to design a comprehensive web-based application. This project will involve several key functionalities, including:

- User authentication: I need registered users to sign in to use the app and have a personalized experience.
- Data storage and retrieval: The application is expected to handle large volumes of data which will be stored and retrieved as per user requirements.
- Payment Gateway Integration: The app will support financial transactions, so integration with a secure, reliable payment gateway is necessary.

Moreover, I also require some essential features for my application:

- User management: The ability to handle various user types, authorize access and manage user roles.
- Data analysis and reporting: The app needs to retrieve data and present analytically coherent reports.
- Third-party API integration: It would be advantageous if the freelancer can link external applications via APIs to improve the app's usability and features.

Skills and experiences:
- Expert in web-based application development
- Strong grasp of data management
- Proven experience with payment gateway integration
- Knowledge and experience in user management
- Good understanding of data analysis and reporting
- Proficiency in external API integration.