.NET Architecture & System Design Interview Question #165
What is API rate limiting from a security perspective?
Security Architecture, Multi-Tenancy & Disaster Recovery Senior Advanced
Quick Interview Answer
Rate limiting restricts request volume and can reduce abuse, brute-force attempts, accidental loops, and resource exhaustion. Limits may be applied per IP, user, API key, tenant, route, or another identity.
Detailed Explanation
Rate limiting restricts request volume and can reduce abuse, brute-force attempts, accidental loops, and resource exhaustion. Limits may be applied per IP, user, API key, tenant, route, or another identity.
Rate limiting is one defensive layer, not a complete denial-of-service solution. Distributed attacks may require upstream protection, traffic filtering, quotas, and infrastructure-level controls.
Code Example
Client -> Rate Limiter -> API
Exceeded policy:
HTTP 429 Too Many Requests