Production pages are not accidentally set to noindex

An unconditional noindex tag is the single most destructive SEO defect possible: it removes the page from every search engine, permanently, until the directive is lifted and the page is recrawled. Common failure modes include a staging-site robots: { index: false } copied to production, a tutorial snippet left in app/layout.tsx that poisons every child route, and CMS preview flags that leak into published content. Recovery is not instant — even after removing the tag, pages often take weeks to return to prior rankings.

Audit every metadata.robots export and every <meta name="robots"> tag for unconditional noindex or { index: false } values. Gate any legitimate non-production noindex on process.env.NODE_ENV or a deployment-environment check — never a static false.

// Correct: only noindex when NOT in production
export const metadata = {
  robots: {
    index: process.env.NODE_ENV === 'production',
  },
}

Also inspect next.config.js headers and any middleware setting X-Robots-Tag: noindex — those override metadata and are easy to miss.