FusionAuth is a developer-focused authentication and user management platform that provides a comprehensive suite of features including registration, login, passwordless authentication, social login, multi-factor authentication (MFA), single sign-on (SSO), and user management. It is designed to be easily integrated into applications of any size, from startups to enterprises, and offers secure, single-tenant deployment options either on-premises or in private clouds. With a strong emphasis on security and compliance, FusionAuth supports a wide range of industries including healthcare, gaming, retail, and fintech, and has demonstrated significant traction with over 15 million developers using its solutions.