I am seeking a senior-level Wix Technical SEO and Speed Optimization expert to rescue and rebuild the backend architecture of my e-commerce store. My site has experienced a significant indexing drop (from 5,000+ pages to under 400) due to heavy HTML code bloat (220kb+ document size), poor mobile performance, and broken internal routing. The Golden Rule: Due to strict payment gateway compliance, you are hired strictly for the technical engine. You must NOT modify, edit, or overwrite any visible On-Page text, Meta Titles, Meta Descriptions, or Product Names. Any violation of this rule will result in immediate contract cancellation. Scope of Work: 1. Indexing & Crawl Rescue - Diagnose and fix the massive indexing crash. - Rebuild and submit a clean XML Sitemap via GSC API. - Optimize Robots.txt and resolve Orphan Pages. 2. Speed & Core Web Vitals - Reduce the 220kb HTML Document Size and code bloat. - Compress and defer 44+ server requests. - Implement WebP image delivery and Lazy Loading. - Preload web fonts and defer non-essential CSS/JS. 3. Site Architecture & Internal Routing - Map and execute 301 Redirects for all 404 errors. - Enforce strict Self-Referencing Canonical Tags and Pagination code. - Create a custom 404 Rescue Page with a search bar. - Implement dynamic Breadcrumb Navigation. - Fix all broken outbound external links through a deep scan. 4. Hidden Code & Advanced Schema - Restructure the H1–H3 HTML hierarchy in the backend code. - Automate generic Image ALT-Text (strictly no brand names). - Inject E-commerce, Organization, and Breadcrumb JSON-LD Schema. 5. Risk Mitigation & Tracking - Run a Toxic Backlink Audit and submit a Disavow file to Google. - Setup GA4 E-commerce Revenue Tracking. - Install Google Tag Manager (GTM) and configure the Meta/Facebook Pixel. - Setup invisible ReCAPTCHA on contact forms and checkout.