Custom Directory SEO Upgrade

My business-listing directory is entirely custom built with JavaScript/Node.js, so every change must happen directly in the codebase. I’m looking for someone who can step in at the technical level, audit the current setup, and ship real fixes—not just a report.

Core objectives
• Reshape the URL structure so it reads cleanly, follows best practice hierarchy, and eliminates any duplicate paths.
• Add correct canonical tags site-wide to resolve duplication signals.
• Repair on-page SEO elements that are holding us back: meta titles, meta descriptions, H1/H2 hierarchy, image alt text, internal linking logic, and any stray indexing or crawl anomalies.

Deliverables (all must be implemented in the live code)
1. Documented URL plan plus committed route changes.
2. Canonical tag logic integrated into our templating.
3. Updated meta, heading, and alt tags pushed to production.
4. Internal link structure refined to spread equity logically through the directory.
5. Indexing issues cleared in Google Search Console and a fresh XML sitemap submitted.
6. A concise hand-off note outlining what was changed and how to maintain it.

Success looks like a page structure that validates in every major crawler, no duplicate-content warnings, and measurable lifts in impressions for key pages within the next indexing cycle. If you have deep technical SEO experience and can code comfortably in a Node environment, I’d like to hear how you would tackle this and how quickly you can start.