01What actually goes wrong
The failures are rarely dramatic and always expensive: a bare domain whose A record quietly vanished, so the address on the business cards stops working while www still does. A www that was never provisioned at the host, so half the links in the wild fail certificate checks. A registrar's domain forwarding fighting the hosting records. A verification TXT record someone tidied away. I've diagnosed every one of these on client domains this year.
02What I do
A registrar and DNS audit with every record explained in plain English. Apex and www set up or repaired, with the redirects to match. Certificates that renew themselves. Email authentication — SPF, DKIM and DMARC — so your messages land and nobody can send as you. Migrations between hosts that keep every ranking page. And a written record of all of it, so the next person (or you, at 11pm) can see what's what.
03Access, done safely
I never ask for your registrar password. Registrars and hosts all support delegate or collaborator access; that's how it's done, and it's how you keep control.