A rate limiter answers one question on every request: has this client made too many calls, and should I reject this one? It sounds trivial until you have twenty API servers behind a load balancer and none of them agree on the count. Why you need one Without a limit, a single misbehaving client ...
Source: [Dev.to](https://dev.to/roni_das_b1b76c5ee6583027/designing-a-rate-limiter-token-bucket-vs-sliding-window-and-making-it-distributed-1lh5)