Day 79: Advanced Authentication Systems
Building Production-Grade Multi-Factor, OAuth2, and Risk-Based Authentication
What We’re Building Today
Today we implement authentication mechanisms that protect billions of user accounts at companies like Google, GitHub, and AWS. We’ll build:
Multi-Factor Authentication (MFA) with TOTP, SMS, and backup codes
OAuth2/SAML provider for enterprise single sign-on
Advanced session management with device fingerprinting and Redis
Risk-based authentication that adapts security based on behavior patterns
Device tracking system monitoring login patterns across 50+ device attributes
