Why it matters
Search equity lives at specific URLs. Change them without a plan and engines meet a wall of dead ends while your rankings transfer to nobody. The horror stories ("traffic halved after the beautiful new site launched") are almost always migration hygiene, not the design.
How it works
A safe migration inventories every URL and its traffic, maps each to a destination, ships one-to-one redirects at launch, keeps titles and content parity for key pages, resubmits sitemaps, and then watches Search Console for weeks. Boring, procedural, and worth every checklist line.
What to do about it
Treat "we're relaunching the website" as an SEO project with a design attached, not vice versa. Ask whoever's building it for the redirect map before you ask for the moodboard.
