SSO is load-bearing — break it and everyone is locked out of everything at once. So we never flip a switch. Keycloak goes live behind Okta first, your applications move one at a time against a parallel environment, and only then is Okta peeled away in layers. No outage. No cutover day. No mass re-credentialing — and every step rolls back in minutes.

The one honest exception is a single MFA re-enrollment per user, staggered on their next login — never a reset event. We say so up front, because the rest of this only matters if you can trust it.

The trick that makes this zero-outage: Keycloak federates to Okta as an upstream identity provider, so it becomes your login front door without changing a single app's credentials. Okta keeps validating passwords and MFA while apps quietly move onto Keycloak. Once every app trusts Keycloak, we move the password source of truth, then MFA, then switch Okta off — each layer independently, each reversible. You are never betting the company on one big cutover.