API Security Rate Limiting

Rate limiting is the practice of restricting the number of requests a client can make to an API within a time window. Rate limiting prevents abuse (credential stuffing, scraping, DDoS), ensures fair resource usage, and protects infrastructure from overload. Implementation requires choosing an algorithm (fixed window, sliding window, token bucket), storage backend (in-memory, Redis), and deciding what to rate-limit (IP, user ID, API key). Rate limiting is a layers defense: edge (Cloudflare), gateway (Kong), server-side. Layered defense is better than any single layer.