Design an IAM system for services and users
Company: Coupang
Role: Software Engineer
Category: System Design
Difficulty: medium
Interview Round: Onsite
## System Design Prompt
Design an **Identity and Access Management (IAM)** system for an organization/platform.
The system must support:
- Human users and service identities (workloads)
- Authentication (who are you?) and authorization (what can you do?)
- Managing permissions via roles/policies
- Auditing and compliance reporting
### Requirements
- Multi-tenant support (multiple orgs/projects/accounts)
- Fine-grained permissions (resource + action)
- Temporary credentials for services (no long-lived secrets if possible)
- API access control for internal microservices
- Admin UI/CLI for managing users/roles/policies
### Deliverables
- Core data model (principals, resources, roles, policies)
- AuthN/AuthZ flows and token format
- Policy evaluation approach
- Auditing, revocation, and key rotation
- Key trade-offs and scaling considerations
Quick Answer: This question evaluates understanding of Identity and Access Management concepts including authentication and authorization flows, role- and policy-based permissions, temporary credential handling, multi-tenant access control, auditing, and scalability considerations.