Question: I need a system that provides robust identity authentication and authorization for my online platform, what options do you have?

If you need a serious identity authentication and authorization system, Auth0 is a good option. It provides access control, integrates with more than 30 SDKs and Quickstarts, and offers Universal Login, Single Sign On, Multifactor Authentication and customizable actions. It's flexible and scalable, so it's good for startups and big businesses.

Another contender is Clerk, a full-stack user management service that handles authentication and user management. It comes with a library of embeddable UI components, flexible APIs and admin interfaces to handle different authentication needs like multifactor authentication, social sign-on and secure password authentication. Clerk also has multi-tenancy support with custom roles and permissions, so it's good for managing user identities.

PropelAuth is geared for fast deployment and can accommodate companies with self-service UIs, SAML, roles/RBAC and multiple sign-in methods. It has flexible pricing and advanced security options like custom session timeouts and MFA enforcement. It's a good choice for B2B products that need to ensure a secure and smooth user experience.

If you want a service that combines identity management with security and compliance, check out Signicat. The digital identity service offers identity proofing through eID Hub and biometric authentication, secure login and electronic signing. It supports more than 170 identity methods and multiple data sources, so it's good for regulated industries like finance and healthcare.