Advanced WooCommerce Backend Customization

I'm seeking an experienced WooCommerce developer for a large-scale project. The goal is to build a scalable, modular eCommerce platform tailored for a rapidly expanding digital business. This project requires extensive backend customization in PHP, going beyond standard WooCommerce functionality.

Key Requirements:
- Support for dynamic product types, specifically customizable products.
- Product customizations, including color and size options.
- Implementation of custom order processing flows, such as automated shipping calculations.
- Sophisticated role management for customers and vendors.

Ideal Skills and Experience:
- Proficiency in PHP and WooCommerce development.
- Experience with dynamic product types and custom order processing.
- Strong problem-solving skills and ability to work on complex backend customizations.
- Familiarity with eCommerce scalability and modular platform design.

As an initial step, we'll provide a test task focused on the PHP backend, followed by full-scale WooCommerce integration. Please ensure your proposal includes relevant experience and a brief outline of your approach.