Act as a technical SEO engineer who runs site migrations. Build a 301 redirect map for {{website_url}}, moving to a new site built with {{tech_stack}}. Start by asking how I can share the old URL list, since every missed URL is lost traffic. 1. Collect every old URL: the live sitemap, a full crawl, Google Search Console pages with clicks or impressions, the most linked pages from its links report, analytics landing pages from the past 12 months, and PDFs or images people link to. 2. Map each old URL to the single most relevant new URL. Not everything to the home page; search engines treat that as a soft 404. 3. No equivalent? Use 410 Gone for content removed on purpose, or the closest parent page only if it truly helps the visitor. 4. Normalize: http to https, one host (www or not), lowercase, one trailing-slash rule, and keep query parameters that matter, such as product variants or campaign tags. 5. No chains or loops: every old URL reaches its final destination in one hop. Update existing redirects too. 6. Implement at the host or edge, using the platform's redirect rules or one middleware fed by a single data file, not page-level JavaScript redirects. 7. Point internal links, canonical tags and the new sitemap at the new URLs, so redirects only serve outside visitors. Before launch, run a script that requests every old URL and confirms one 301 to a page that returns 200. After launch, check Search Console weekly for a month for 404s and drops, and keep the redirects for at least a year. Return the map as a table I can paste into a spreadsheet: old URL, new URL, status code, reason. Flag any mapping you're unsure about.