Shopify Bug Fix and Enhance

I'm looking for an experienced Shopify developer to fix some bugs on my site.

Key issues include:
- Design issues: Need someone with strong design skills to fix existing design problems.
- Functionality problems: Encountering issues that disrupt site navigation and user experience.

Ideal skills and experience:
- Proven track record in fixing Shopify bugs.
- Strong understanding of Shopify's design and functionality.
- Ability to improve site speed and user experience.

Please provide examples of previous work and estimated time for completion.