CIAM Architecture Patterns: Designing Customer Identity for Millions of Users
Workforce IAM and CIAM look similar on a whiteboard — both authenticate users and manage access. But the architecture is fundamentally different when your user base goes from 5,000 employees to 5 million customers. The scaling problems, the UX requirements, and the regulatory constraints all change. This guide covers the architectural patterns that make CIAM work at scale, drawn from real deployments. Why CIAM Needs Different Architecture Concern Workforce IAM CIAM User count 1K - 100K 100K - 100M+ Registration IT-provisioned Self-service Identity source Corporate directory Social + email + phone Session duration 8-hour workday Weeks to months Latency tolerance 500ms acceptable 100ms expected Consent management Minimal GDPR/CCPA mandatory Branding Consistent corporate Per-product customization Availability target 99.9% 99.99%+ You can’t take an Okta workforce deployment, add more users, and call it CIAM. The data model, the session architecture, and the user experience are structurally different. ...