Rate limiting is the frontline defense of modern backend infrastructure. Without rate limiters, any misconfigured client script or malicious actor can exhaust server thread pools and downstream database connections within seconds.

1. Mathematical Tradeoffs of Rate Limiting Algorithms

Algorithm Burst Tolerance Memory Overhead Distributed Complexity
Fixed Window Counter Poor (2x burst at boundary) Minimal (1 counter) Low
Sliding Window Log Precise High (Logs all timestamps) High memory cost
Token Bucket Optimal (Controlled burst) Minimal (2 fields) Industry Standard
Advertisement / Sponsored