Next.js 15 Authentication Complete Guide - Best Practices and Pitfalls

Learn comprehensive authentication implementation in Next.js 15 through this 38-minute tutorial that covers essential security concepts, best practices, and common pitfalls. Explore fundamental authentication concepts including what should be protected in Next.js applications, cookies and JWT tokens, and the decision between external authentication solutions like Kinde versus building your own system. Master the complete setup process for Kinde authentication service and discover how to protect different parts of your application including server components, routes, server actions, and route handlers. Understand critical architectural decisions such as where to implement authentication checks - comparing layout versus page components and middleware versus page-level protection. Navigate important pitfalls including using server actions on unprotected routes, static versus dynamic rendering considerations, and the common mistake of forgetting proper authorization. Implement client-side authentication features like displaying user information in headers with avatars and email addresses. Connect external authentication solutions with your own database and implement advanced features like roles and permissions with admin functionality. Apply the Data Access Layer (DAL) pattern as a best practice for secure data handling in authenticated applications.