How would you diagnose a JavaScript SEO problem?

1. Raw HTTP response.
2. Browser-rendered DOM.
3. Google Search Console URL Inspection.
4. HTTP status.
5. robots directives.
6. canonical.
7. links.
8. structured data.
9. JavaScript console/runtime errors.
10. API/resource requests.

Look for differences between what the server initially sends and what becomes available after rendering.

Common failures include:

• content only available after failed API requests;
• important links created by non-crawlable interactions;
• canonical changed incorrectly;
• noindex injected unexpectedly;
• resources blocked by robots.txt;
• hydration errors;
• inconsistent rendering.