Refactor WooCommerce Plugin for Jortt API

I'm seeking an experienced developer to refactor a WooCommerce plugin for the Jortt accounting API. The goal is to make the plugin future-proof, modular, and fully compatible with both legacy WooCommerce setups and the latest versions using High-Performance Order Storage (HPOS).

Key Requirements:
- Refactor the current plugin into a clean, maintainable, and modular structure (split across logical files)
- Replace outdated WordPress hooks (save_post, update_post_meta) with WooCommerce CRUD-based and HPOS-compatible methods
- Preserve backwards compatibility with WooCommerce versions prior to HPOS
- Modernize API handling (Jortt REST API) and improve error logging and response validation
- Ensure the plugin remains testable, with clear separation of responsibilities (hooks, logic, settings, API)
- Maintain or improve the current admin interface and settings

Ideal Skills & Experience:
- Strong expertise in WordPress and WooCommerce plugin development
- In-depth understanding of WooCommerce architecture, including HPOS and the CRUD order system
- Proven experience with REST API integrations
- Solid grasp of modular design patterns in PHP (OOP or well-structured procedural)
- Experience writing plugins that support both older and current WooCommerce setups
- Attention to clean code, edge case handling, and plugin performance

Testing & Access:
- Developer must be able to test the plugin in their own local or staging WooCommerce environment
- A free test account can be created at https://www.jortt.nl to access the Jortt API for development purposes

Deliverables:
- Refactored plugin code in a modular structure, ready to be dropped into /wp-content/plugins/
- Clear file organization (e.g., api/, hooks/, admin/, etc.)
- Inline documentation and a concise README.md
- Summary of structural changes and best-practice decisions

Optional: Git repository for versioned delivery

Please include examples of previous WooCommerce plugins or API integrations you've worked on. Preference will be given to developers who can demonstrate familiarity with HPOS or modular plugin architecture.

Looking forward to your proposals!