Senior PHP (CodeIgniter 4) Developer Needed for Directory Site Upgrade (AliExpress.online), DB Optimization, Dynamic SEO, IndexNow & Sitemap Enhancements

I am looking for an experienced Full-Stack PHP Developer (CodeIgniter Expert) to upgrade, optimize, refine, and enhance my existing website directory: www.Aliaxpress.online ​The website is currently built on CodeIgniter 3 (CI3) with a MySQL database. My primary objective is to fully migrate the site to CodeIgniter 4 (CI4), optimize database performance, fix dynamic URL slug issues, build an advanced dynamic SEO engine with IndexNow API integration, implement a structured XML Sitemap Index, and polish the overall site & admin UI/UX. ​Key Tasks & Responsibilities (Point-by-Point): ​1. Framework Upgrade (CI3 to CI4): ​Migrate the entire AliExpress.online project from CodeIgniter 3 to CodeIgniter 4 (Latest Version). ​Refactor existing legacy code to follow clean MVC architecture, OOP principles, and modern PHP/CI4 security standards. ​2. Database & Server Optimization (MySQL): ​Perform MySQL database optimization (query performance, indexing, garbage data cleanup). ​Fix high server resource consumption and resolve background performance bottlenecks. ​3. Dynamic URL Slug Management (Fixing URL Update Bug): ​Fix Slug/URL Auto-Update Issue: Currently, when updating a Website Listing or Blog Post title/content, the URL slug does not update or regenerate properly. ​Implement a robust Dynamic Slug Generator that correctly updates permalinks/URLs when posts, listings, or categories are modified (with proper redirects/canonical management). ​4. Advanced Dynamic SEO Engine: ​Dual SEO Setup (Default vs. Custom/Overridden): ​Global/Default SEO: Fallback setup for Meta Title, Meta Description, Keywords, Open Graph (OG tags), Twitter Cards, and dynamic Canonical URLs (auto-generated using Base URL). ​Custom SEO Override: Ability to set custom SEO meta tags specifically per Page, Category, or Website Listing. ​Dynamic Template Variables: ​Support dynamic placeholder variables in SEO templates (e.g., {category_name}, {website_name}, {site_title}, etc.). ​Example: "Top Services in {category_name}" should render "Top Services in Mobile" on the Mobile category page to prevent identical/duplicate meta tags. ​Excerpt Fields for SEO Snippets: ​Add an Excerpt field to both the Website Listing form (Admin/User) and the Blog Post form. ​The excerpt should automatically serve as the default Meta Description snippet for detail pages. ​5. IndexNow Integration (Bing & Search Engines API): ​Admin Key Management: Add an admin section to easily insert and manage IndexNow API keys / Secret keys. ​Instant & Cron Job Submission: Automatically submit new or updated URLs to IndexNow instantly upon creation/editing, combined with a automated Cron Job setup to scan and push new URLs. ​404 / Removed URL Handling: Automatically send removal/deleted signals or clean up URLs returning 404 status from search engine indexing queues. ​6. Dynamic XML Sitemap Index Architecture: ​Upgrade the current monolithic sitemap into a clean, structured XML Sitemap Index (sitemap_index.xml / sitemap.xml). ​Split URLs dynamically into clean sub-sitemaps: ​Pages Sitemap (pages-sitemap.xml) ​Website Listings Sitemap (listings-sitemap.xml) ​Listing Categories Sitemap (categories-sitemap.xml) ​Blog Posts Sitemap (blog-sitemap.xml) ​Blog Categories Sitemap (blog-categories-sitemap.xml) ​Ensure strict XML formatting compliant with Google & Bing Webmaster standards. ​7. Blog System & WordPress Importer: ​Blog Redesign: Redesign and modernize the layout for the Main Blog Page, Blog Detail Page, and Blog Category Page. ​WordPress XML/CSV Import Feature: Build an Admin tool to import exported WordPress blog posts (including featured images, categories, and content) directly into our custom database. ​8. UI/UX Refinement & Admin Panel Upgrade: ​Admin Panel UI Redesign: Modernize the current plain admin dashboard into an attractive, intuitive dashboard. ​Website Submission Review Screen: Redesign the admin submission view so pending user-submitted directory websites can be previewed/reviewed clearly before approval. ​Core Public Pages Refinement: Polish design and layouts for: ​Home Page ​Directory Listing & Category Pages ​Website Detail Page ​Partner, Friend, About Us, and Contact Pages ​9. Speed & Performance Optimization: ​Achieve 95%+ score on Google PageSpeed Insights (Desktop and Mobile). ​Minify CSS/JS assets, implement lazy loading, set up proper image caching, and optimize resource loading. ​10. Minor Tweaks & Final Refinements: ​Be open to handling small, minor UI adjustments or bug fixes discovered during the upgrade and testing process. ​Required Qualifications: ​Expert knowledge of CodeIgniter 3 & CodeIgniter 4 (PHP 8.x). ​Deep experience in MySQL Database Optimization and Indexing. ​Experience with IndexNow API implementation & Cron Job automation. ​Deep understanding of SEO Architecture, XML Sitemaps, Canonical URLs, and Dynamic Templating. ​Strong Frontend UI/UX Skills (Bootstrap / CSS3 / JavaScript). ​Proven track record of achieving 95+ Google PageSpeed Scores. ​How to Apply: ​Please respond with: ​Examples of previous CodeIgniter 4 projects you have built or upgraded. ​Proof or case studies of websites where you achieved 95+ Google PageSpeed scores. ​A brief explanation of your experience with IndexNow API and Dynamic XML Sitemap Indexing. ​Estimated timeline and budget breakdown for this project. ​Looking forward to working with a skilled developer!