Authentication for applications often starts simply with features like signup, login, and password resets, but as a company grows, especially in the B2B SaaS sector, the complexity increases significantly. This growth journey is exemplified by the fictional company Acme, which uses a project management tool called Circular. Initially, Acme's authentication needs were basic, but as they expanded from a small team to a company with hundreds of employees, their requirements evolved to include organization management, role-based permissions, and eventually integration with Identity Providers for centralized access control. This progression highlights the challenges of managing access across multiple tools and the benefits of Enterprise Single Sign-On (SSO) and SCIM provisioning to streamline employee onboarding and offboarding. Larger companies often request custom authentication features to meet their specific needs, which can divert resources from core business functions unless outsourced to specialized authentication providers like PropelAuth, which offers solutions to manage these complexities efficiently.