Shopify App Development for Marketplace Integration

I need a proficient developer to create a Shopify app for my existing online store. This app will interface with a marketplace API and needs to perform various crucial tasks. The budget for this project is 300 USD, with a deadline of 14 working days.

Key Functionalities:
- Sync product listings
- Manage orders
- Update inventory
- Sync prices

Integration with Existing Features:
- Product listings
- Menu categories

Design:
- The interface of the Shopify app should be simple and functional. No need to match my online store's design or adhere to the marketplace's design guidelines.

Ideal Skills:
- Extensive experience in Shopify app development
- Proficient in API integration
- Capable of creating user-friendly interface designs
- Knowledgeable about syncing product listings, managing orders, updating inventory, and syncing prices.

This is a great opportunity for a skilled professional to make a significant impact on my online business. Looking forward to your proposals.

API documentation with structure:
https://integration.staging.tazz.ro/v1/docs/