Multi-Category E-Commerce Website Development

I'm looking for a skilled developer to create an e-commerce website for selling physical goods. The site should have multiple product categories.

Essential Requirements:
- User-friendly interface
- Multiple product categories
- Secure payment gateway integration
- Mobile responsiveness
- SEO optimization

Ideal Skills and Experience:
- Proven experience in e-commerce website development
- Strong knowledge of payment systems
- Familiarity with SEO best practices
- Experience with responsive design

Please share your portfolio and relevant experience.