Custom Visa/Mastercard Payment Gateway

I need a custom-built payment gateway that allows my service-based business to accept payments via Visa and Mastercard.

Key requirements:
- Secure processing of Visa and Mastercard transactions
- User-friendly interface for customers
- Integration with existing website or platform
- Compliance with all necessary regulations and security standards (e.g., PCI DSS)

Ideal Skills and Experience:
- Experience in developing secure payment gateways
- Knowledge of payment processing and financial regulations
- Strong background in web development and integration
- Expertise in cybersecurity

Please provide a portfolio with similar projects and an estimated timeline for completion.