Launch day: the exact order of operations

Put one site live in an order where nothing becomes public until everything private is proven: content served from the destination host, then a certificate answering on the real hostname, then the indexing controls, and only then the domain pointed at any of it. Pointing the domain is the one step a stranger can witness, so it goes last. Everything before it can be corrected quietly.

The two rules the order comes from

• The first visitor and the first crawl must not see a half state. A domain resolving to an empty docroot, a certificate warning, or a page still carrying staging controls is a first impression that gets cached and sometimes indexed.
• Buy the reversal before you need it. Time to live is set by the record you are replacing, so shortening it does nothing at the moment of the change. Shorten it days ahead and a bad cutover unwinds in minutes.

The sequence

Each step names what must be true before it starts, and what proves it finished. Never start a step whose precondition is unproven.

1. Shorten the time to live on the records you will change. Precondition: the current record set is written down. Success test: an authoritative query returns the shorter value, and one full length of the old value has since elapsed.
2. Create the destination space and confirm it answers. Precondition: the site-to-account and site-to-address assignment was decided earlier, not now. Success test: a request reaching the destination directly returns a file you placed there, not a placeholder.
3. Deploy the complete content set. Precondition: the destination answers. Success test: every internal reference resolves inside the deployed copy, and the page count matches what you meant to publish.
4. Issue the certificate for the production hostname. Precondition: a validation method that does not need the domain pointed here yet, meaning DNS-based validation. Success test: the chain is complete for the bare hostname and the www form, and the expiry is recorded. See SSL certificates.
5. Set canonical, robots and sitemap to production values. Precondition: content final, hostname settled. Success test: a fetch returns a canonical equal to the production URL, and no robots rule blocks what you want crawled, per Google's Search documentation.
6. Remove every staging block. Precondition: steps one to five verified. Success test: an unauthenticated request from a network you do not control returns the page with no password prompt, no address restriction and no noindex.
7. Point the domain. Precondition: everything above green, and the short time to live in effect long enough to be the cached value. Success test: every nameserver in the delegated set agrees, and so does an outside resolver.
8. Check the first live impression. Precondition: the name resolves to the new destination. Success test: plain HTTP reaches secure in one hop, the page loads with no mixed content, and older forms of the address redirect in one hop rather than three.
9. Restore the time to live and register the property. Precondition: the site has been correct in public long enough that you would not revert it. Success test: the longer value is authoritative again, and the sitemap was submitted from the verified property.

Why the certificate cannot wait until after

If the name points at the host before a valid certificate exists there, the gap between those two events is served insecurely or behind a browser warning. That gap is short in your calendar and permanent in whatever fetched during it. Validating by DNS record, rather than by serving a file at the live address, lets the certificate exist before the name moves.

Treat every step as a gate

A written success test turns "I did that" into "I saw that". Most failed launches are steps performed correctly on the wrong target: files on the previous account, the certificate on the staging hostname, the sitemap in another site's property. Reading the result from outside your own machine catches all three. When something breaks after the cutover, revert the record first and diagnose second: that is what the shortened time to live bought you. Follow-up belongs in diagnostics.