Design a distributed rate limiter for an API serving millions of requests per second.

Every API platform needs one. Interviewers reward the candidate who picks the right algorithm (token bucket vs sliding window) for the burst behavior, then cracks the genuinely hard part: holding one shared limit across many servers without a per-request round trip to a central store.

Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.