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Vibe codingHardvc-g044
Subject Ai code reviewLevel Senior–Staff~20 minCommon in Networking & APIs interviewsIndustries Software development, Technology

Question

An AI assistant wrote this Python sliding-window rate limiter: allow at most `limit` requests per `window_seconds` per key. It produced:

python
import time buckets = {} def allow(key, limit, window_seconds):    now = time.time()    times = buckets.get(key, [])    times = [t for t in times if now - t < window_seconds]    if len(times) < limit:        times.append(now)        buckets[key] = times        return True    buckets[key] = times    return False

It blocks the (limit+1)th rapid request in a quick test. What's wrong, and what makes it fail in production?

What a strong answer looks like

Treat the AI’s output as a draft to verify, not an answer to trust. Name the specific flaw and the input that triggers it, say how you’d catch it — tests, edge cases, reading critically — and how you’d re-prompt or decompose to get it right.

Learn the concepts
Describe your solution

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.