Refactored the manual meta tag implementation in Astro to address critical SEO deficiencies using the astro-seo package. The migration improved canonical URLs, language declarations, and Open Graph tags while adding per-page indexing control.

Issue

The static site suffered from multiple SEO deficiencies:

Missing canonical URLs, risking duplicate content penalties.
Incorrect language declarations (lang="en" despite German content).
Incomplete Open Graph tags (missing og:url, og:locale, og:site_name).
Relative image URLs in Open Graph tags breaking social media previews.
No sitemap reference in the <head> section.
No per-page indexing control, causing privacy/legal pages to appear in search results.
Maintenance burden from inconsistent manual meta tags across 20+ lines.

Culprit

Manual Meta Tag Management: Meta tags were constructed without validation, leading to inconsistencies.
Architecture Decision: The props interface assumed relative paths were sufficient but failed for social media crawlers.
Language Mismatch: Hardcoded lang="en" despite the site’s German content.
Image URL Handling: Relative paths broke when shared on social media.

Solution

Package Integration: Installed astro-seo@0.8.4 for type-safe SEO implementation.
Layout Component Refactor: Replaced manual meta tags with a single <SEO> component in Layout.astro, auto-generating canonical URLs and absolute image paths.
Per-Page Indexing Control: Added noindex and nofollow props for privacy/legal pages.
Complete Open Graph Implementation: Ensured all required Open Graph tags were included with correct locales and site names.
Sitemap Reference: Added a link to the sitemap in the <head> section.
Verification: Confirmed proper generation of canonical URLs, Open Graph tags, and indexing controls in the build output.