A place to store my thoughts when designing a globally distributed high scale e-commerce system
Authentication is the gateway to any successful large-scale, high-traffic e-commerce platform. It must handle hundreds of thousands of users seamlessly, safeguard their data, and ensure a smooth, secure experience.
- High Concurrent Requests: Handle thousands of users simultaneously during big sales events.
- Horizontal Scalability: Scale easily during peak times by adding more servers.
- Multi-Region Deployment: Serve users globally with minimal latency.
- Redundancy & Failover: Automatic switchovers to keep the system running smoothly during failures.
- Multi-Factor Authentication (MFA): Add layers of security for critical user accounts.
- Risk-Based Authentication: Dynamic security based on user behavior, device, and location.
- Token-Based Access: Issue and verify tokens, ensuring stateless, secure interactions.
- Bot/DDoS Protection: Rate limiting and CAPTCHAs to fend off attacks.
- Password Spray & Replay Attacks: Detect and block repeated or recycled login attempts.
- MITM, Phishing, and Session Hijacking: SSL encryption, certificate pinning, and user prompts for anomalies.
- CSRF & Account Enumeration: CSRF tokens, generic error messages, and rate limiting to prevent abuse.
- DDoS, Password Reset Abuse, Fake Accounts: Rate limiting, CAPTCHA, and user alerts for strange activity.
- Token Refresh: Stay logged in without re-authenticating.
- Token Revocation: Instantly invalidate compromised tokens.
- Secure Token Storage: Keep tokens safe using HttpOnly cookies or secure mobile storage.
- Session Control: Users can manage their active sessions and log out from others.
- Privilege-Based Token Lifetimes: Shorter lifetimes for higher privilege tokens (e.g., admin).
- Low Latency: Quick responses during logins, even during peak traffic.
- Authentication Logs & Audit Trails: Log every login attempt for compliance and analysis.
- Anomaly Detection & Alerts: Track and alert unusual login behaviors.
- Passwordless Magic Links: Quick access without remembering passwords.
- Social Logins: One-click logins using Google, Facebook, etc.
- Progressive Profiling: Collect only minimal data upfront; gather more as needed.
- Restorable Sessions: Regularly backup, and be able to recover session data seamlessly during disruptions.
- GDPR Compliance: Full account deletion capability.
- Minimal Information Collection: Respect privacy, collect only what’s needed.
To handle up to 50,000 concurrent users without being limited by budget constraints, Keycloak is the best choice.
It's open-source, offers extensive features, requires self-managed infrastructure, and has no monthly active user limits, keeping costs low compared to managed options. While options such as Auth0 provide more functionality and scaling, costs could extend into the thousands with the level of traffic we are expecting.
