Rate limiting protects your API from abuse and ensures fair usage. Here are proven algorithms and implementation patterns for production systems.
Why Rate Limit?
Protection against:
- DDoS attacks
- Brute force attempts
- API abuse
- Resource exhaustion
- Unfair usage
Business benefits:
- Predictable costs
- SLA enforcement
- Monetization tiers
- Quality of service
Token Bucket Algorithm
Sliding Window Algorithm
Redis-Based Distributed Rate Limiting
Express Middleware
Response Headers
Tiered Rate Limiting
Best Practices
DO:
✓ Use distributed storage for multi-instance
✓ Return informative headers
✓ Implement graceful degradation
✓ Different limits for different endpoints
✓ Consider user tiers
✓ Log rate limit events
DON'T:
✗ Rate limit health checks
✗ Use only IP-based limiting
✗ Set limits too low for normal usage
✗ Forget to handle edge cases
✗ Ignore legitimate high-volume users
Conclusion
Rate limiting is essential API protection. Choose the right algorithm for your use case—token bucket for bursts, sliding window for smooth limits—and use distributed storage for scaled systems.
Always communicate limits clearly through headers and error messages.