[Phase 3] Performance optimization and SEO

[afucher]

Optimize site performance, add SEO metadata, and ensure best practices.

Deliverable

A fast, discoverable documentation site that ranks well in search engines and loads quickly for all users.

Acceptance Criteria

• Lighthouse audit run:

  • Performance score ≥ 90
  • Accessibility score ≥ 95
  • SEO score ≥ 95
  • Best Practices score ≥ 95
  • Fix any issues reported

• Metadata added to all pages:

  • title frontmatter on every Markdown page
  • description frontmatter (1–2 sentence summary) on all pages
  • OG image set globally in Starlight config
  • Twitter card meta tags configured

• Sitemap generated and submitted:

  • @astrojs/sitemap integration verified in astro.config.mjs
  • sitemap-index.xml and sitemap-0.xml present in build output

• robots.txt created in website/public/:

  • Allow all bots to crawl
  • Point to sitemap URL

• Search engine registration:

  • Google Search Console verified and site added
  • Bing Webmaster Tools verified and site added
  • Initial indexing checked

• Performance metrics verified:

  • First Contentful Paint (FCP): < 2s
  • Largest Contentful Paint (LCP): < 2.5s
  • Cumulative Layout Shift (CLS): < 0.1
  • Total blocking time (TBT): < 200ms

• Mobile responsiveness verified on:

  • iOS Safari
  • Android Chrome
  • Desktop Chrome, Firefox

Related Plan Section

docs-plan.md (general best practices)