Authentication & Authorization Implementation Patterns Build secure, scalable authentication and authorization systems using industry-standard patterns and modern best practices. When to Use This Skill - Implementing user authentication systems - Securing REST or GraphQL APIs - Adding OAuth2/social login - Implementing role-based access control (RBAC) - Designing session management - Migrating authentication systems - Debugging auth issues - Implementing SSO or multi-tenancy Core Concepts 1. Authentication vs Authorization Authentication (AuthN) : Who are you? - Verifying identity (username/p…