Backend
What is Rate Limiting?
A technique that caps how many requests a client can make in a time window to protect services from overload and abuse.
Definition
Rate limiting restricts how many requests a client may send within a given window, returning HTTP 429 (Too Many Requests) once the quota is exhausted. Common algorithms include token bucket, leaky bucket, fixed window, and sliding window log, each trading accuracy against memory cost. Implementations live in API gateways like Kong or Envoy, in NGINX via limit_req, or in application code backed by Redis counters. Well-designed limiters send Retry-After and X-RateLimit-* headers so clients can back off gracefully instead of hammering the service.