ASP.NET Custom Integration Development

I need an ASP.NET web application developed to serve as a custom business solution. The primary function of this application will be to support payment services integration.

Key requirements:
- Payment Services Integration
- Ability to integrate with various payment providers (e.g., PayPal, Stripe, Square)

Ideal Skills and Experience:
- Proficiency in ASP.NET development
- Experience with payment integration
- Strong knowledge of APIs and web application security
- Background in developing custom business solutions

Please provide examples of similar work.