How I Migrated Hundreds of Pages Without Losing My Mind

A first-hand account of migrating hundreds of documentation pages from Docusaurus to Next.js with Markdoc, using a Research-Plan-Implement pattern. The author cataloged all existing pages before touching code, designed a new information architecture, wrote 810+ redirect rules to preserve old URLs, added LLM-friendly endpoints (/llms.txt and a raw markdown API), and set up automated link checking in CI. The post argues that doing thorough research and planning upfront prevents the cascading decision problems that typically derail large migrations.