Authentication & Authorization Interview Questions

Next.js supports multiple authentication methods: JWT, session-based, OAuth providers, NextAuth.js library. Can implement custom authentication or use third-party solutions. Supports both client and server-side authentication.

NextAuth.js is a complete authentication solution for Next.js applications. Provides built-in support for multiple providers (OAuth, email, credentials). Handles sessions, JWT, and database integration.

Store JWT in HTTP-only cookies or local storage. Implement token verification. Handle token expiration. Support refresh tokens. Manage token lifecycle.

Store session data on server. Use session cookies for client identification. Handle session expiration. Support session persistence. Implement session management.

Configure OAuth providers. Handle OAuth flow. Support callback URLs. Implement user profile retrieval. Manage OAuth tokens.

Implement role checking middleware. Define user roles. Handle permission checks. Support role hierarchies. Implement access control.

Implement authentication middleware. Verify tokens or sessions. Handle unauthorized requests. Support API security. Implement rate limiting.

Implement CSRF tokens. Handle token validation. Support form submissions. Implement security headers. Prevent cross-site request forgery.

Manage user authentication state. Handle state persistence. Support state updates. Implement state management. Handle state synchronization.

Use bcrypt or similar libraries. Handle password storage. Support password validation. Implement secure hashing. Manage salt generation.

Implement token refresh logic. Handle token rotation. Support silent refresh. Implement refresh strategies. Manage token storage.

Configure social providers. Handle OAuth integration. Support user profile mapping. Implement login flow. Manage provider tokens.

Implement granular permissions. Handle permission checks. Support permission groups. Implement access control lists. Manage permission hierarchy.

Support 2FA methods. Handle verification codes. Implement backup codes. Support authentication apps. Manage 2FA setup.

Implement error handling. Support error messages. Handle recovery flows. Implement error logging. Manage error states.

Handle reset flow. Support reset tokens. Implement email notifications. Handle token expiration. Manage reset process.

Implement session storage. Handle session cleanup. Support session validation. Implement session strategies. Manage session state.

Create authentication tests. Handle test scenarios. Support integration testing. Implement test strategies. Manage test coverage.

Track authentication metrics. Handle monitoring integration. Support analytics. Implement monitoring strategies. Manage monitoring data.

Handle authorization code flow. Support refresh tokens. Implement token exchange. Handle scopes. Manage OAuth state.

Implement secure token storage. Handle token encryption. Support token validation. Implement security measures. Manage token lifecycle.

Handle tenant isolation. Support tenant authentication. Implement tenant routing. Handle tenant data. Manage tenant access.

Implement distributed session management. Handle cross-domain auth. Support SSO integration. Implement auth strategies.

Track authentication events. Handle audit trail. Support compliance requirements. Implement logging strategies. Manage audit data.

Implement security standards. Handle data privacy. Support regulatory compliance. Implement compliance measures. Manage compliance reporting.

Design scalable auth systems. Handle system organization. Support architecture patterns. Implement design principles.

Optimize authentication flow. Handle caching strategies. Support performance monitoring. Implement optimization techniques.

Create security test suites. Handle penetration testing. Support vulnerability scanning. Implement security measures.

Implement deployment strategies. Handle environment configuration. Support scaling solutions. Implement deployment patterns.