Shopify Site Theme Customization

I need an experienced Shopify developer to update my existing website. The primary focus will be on theme customization to better align with my brand.

Key Requirements:
- Customize current Shopify theme based on my requirements
- Ensure updates are responsive and mobile-friendly
- Maintain site functionality during and after updates

Ideal Skills:
- Proficiency in Shopify and theme customization
- Strong understanding of web design principles
- Experience with responsive design

Please share examples of similar work done.