system design

Rate Limiter

Design a rate limiting system that controls the number of requests a client can make within a time window. This document covers three common algorithms: token bucket (smooth bursts), sliding window log (precise tracking), and fixed window counter (simple but susceptible to boundary spikes). Key trade-offs include memory usage versus precision, burst tolerance versus strict enforcement, and distributed synchronization overhead. Rate limiters are essential for protecting APIs from abuse, ensuring fair resource allocation, and maintaining system stability under load.