Senior WooCommerce / WordPress Developer (10+ yrs, hand-coded PHP, healthcare e-commerce)

We are a Swiss digital agency that builds and maintains websites for healthcare and medical clients. We are taking over and completing a WooCommerce build for a Swiss online pharmacy, and we need a senior developer who has done regulated, integration-heavy e-commerce work before. This is not a page-builder job. The codebase is hand-written PHP: a custom WooCommerce theme (child theme + Tailwind, custom page and WooCommerce template overrides) plus a class-based integration plugin (roughly 1,750 lines of PHP) that talks to a logistics/ERP backend over XML and SFTP. You will take this over, harden it, finish the incomplete parts, and get it production-ready. Elementor/Divi-only developers are not a fit. What the project involves - Take over an existing, partly finished custom WooCommerce codebase and bring it to production quality - Harden a class-based PHP integration plugin: XML API calls to a supplier backend (availability + order submission), SFTP file exchange, cron-based stock and delivery syncs, shipping-label and delivery-note generation, logging - Build and re-skin a custom WooCommerce theme in PHP + Tailwind (no page builders) - Integrate a pharma product master-data feed (product data, images, categories) - Implement custom pricing logic (per-manufacturer markups, promotions, domain-based discounts) - Migrate all existing customer and order data into the new shop - Multilingual setup (DE / FR) via WPML - Payment gateway, analytics, and product feed integrations Required (please do not apply if you do not meet these) - 10+ years of professional WordPress / WooCommerce development - Strong hand-coded PHP: OOP, custom plugins, WooCommerce hooks/filters, template overrides, solid grasp of the WooCommerce data model. You read and extend other people's PHP comfortably. - Real experience in healthcare, pharmacy, or another regulated e-commerce domain (tell us which) - Proven experience integrating WooCommerce with external systems via REST/XML APIs and SFTP - Experience taking over and finishing an existing codebase, not only greenfield builds - Clean, maintainable, documented code and reliable, responsive communication Strong plus - Swiss / DACH e-commerce experience and German language - Blocksy child theme + Tailwind - Large data migrations (customers + orders) - Automated testing (Playwright) and working to documented SOPs Engagement - Freelance / contract, part-time to start, with a clear runway if it goes well - One-month paid trial on this project. Strong performers continue as our ongoing senior WordPress/WooCommerce developer across further sites. - Please state your hourly rate To apply Start your proposal with the word MATTERHORN so we know you read this. No templates. Be specific about the regulated e-commerce project you are proudest of and the hardest integration you have built or taken over. Screening questions 1. How many years have you worked with WooCommerce, and roughly how many custom, hand-coded (non-page-builder) WooCommerce sites have you shipped? 2. Describe a healthcare, pharmacy, or regulated e-commerce project you built. What made it regulated, and what was your role? 3. Describe an integration you built or took over that used XML and/or SFTP with an external ERP, logistics, or supplier system. How did you handle failures and retries? 4. You inherit a roughly 1,750-line class-based PHP plugin that is unfinished and untested end to end. Walk us through your first week. 5. What is your hourly rate and weekly availability for the next 2 to 3 months?