Rate limiting protects your system from abuse and traffic spikes (often returning HTTP 429). You can enforce it at the edge (CDN/WAF), API gateway/load balancer, and in the app itself. Earlier enforcement saves resources, but the app still needs safeguards because not all traffic comes through one entry point.
Expanding on the short answer — what usually matters in practice:
A tiny example (an explanation template):
// Example: discuss trade-offs for "rate-limiting-in-the-cloud:-where-can-you-enforc"
function explain() {
// Start from the core idea:
// Rate limiting protects your system from abuse and traffic spikes (often returning HTTP 429
}