Advanced Authentication Patterns with Next.js and Supabase Authentication is the gateway to your application. While basic email/password authentication works for simple apps, production applications need sophisticated authentication patterns that balance security, user experience, and business requirements. This guide teaches you advanced authentication techniques used by leading SaaS companies. Authentication Fundamentals Before diving into advanced patterns, understand these core concepts: Authentication vs Authorization: Authentication : Verifies who you are (login) Authorization : Determines what you can do (permissions) Stateful vs Stateless: Stateful : Server stores session data (traditional approach) Stateless : Client stores token, server verifies (JWT approach) Token Types: Access Token : Short-lived (1 hour), used for API requests Refresh Token : Long-lived (7 days), used to get new access tokens ID Token : Contains user information, used for authentication 1.…