Auth0 was recently acquired by Okta, prompting consideration of migration options for developers. When evaluating a new authentication system, it's essential to consider the vendor's trustworthiness and operational complexity. A broad evaluation should include factors such as self-hosted or SaaS models, open-source status, standards support, core functionality, single sign-on capabilities, integrations with other auth technologies, cost, and documentation quality. Feature matrices can help determine requirements and "nice to haves" for each solution. Prototyping is crucial before deciding on a new provider, as it allows testing of the riskiest integration and evaluation of non-standard functionality such as Universal Login. A detailed analysis of Auth0's functionality and its differences from other providers like FusionAuth should be performed, including user data migration, connections, rules, hooks, actions, APIs, applications, SSO integrations, tenants, roles, and permissions. Ultimately, the goal is to find a solution that meets the organization's needs while minimizing operational complexity and ensuring a smooth migration.