To resolve session and authentication issues, ensure your session middleware is properly configured and verify that session tokens are being sent and validated correctly. Check for issues with cookie settings, such as SameSite and secure flags.

Issues with sessions and authentication in a Node.js application can lead to significant user experience problems, making it essential to troubleshoot effectively. Begin by examining your session middleware configuration, ensuring that it is set up correctly in your Express or Koa application. Middleware like express-session should be properly initialized, with parameters such as secret, resave, and saveUninitialized configured to meet your application's needs. Verify that session tokens are being sent with requests and that they match what your server expects. A common problem arises from cookie settings, particularly the SameSite and secure flags, which can prevent cookies from being sent in certain contexts, like cross-origin requests. For instance, if your frontend and backend are hosted on different origins, ensure that the SameSite attribute is set appropriately to allow cookies to be sent. Additionally, check your authentication logic to confirm that session validation is correctly implemented. Review any middleware responsible for checking user authentication before accessing protected routes to ensure they function correctly. Implement thorough logging to capture authentication-related errors, which can aid in diagnosing issues during development and production. By addressing these factors, you can effectively resolve session and authentication issues, ensuring a smoother experience for users.