GitHub

2 design problems known to be asked at GitHub.

Medium1

Mediumhigh level design distributed systems networking

Rate Limiting: How a Bucket of Tokens Keeps Your API Alive

One misbehaving client with a retry loop can take down a service faster than any DDoS. Rate limiting is the cheap, boring control that decides who gets served — here's how the five classic algorithms actually work, and how to make one correct across a fleet.

Asked at Stripe, Cloudflare, GitHub +2

Aug 8, 2026·16 min read

Hard1

Hardsystem design interview algorithms caching concurrency

Design a Distributed Rate Limiter

Picking token bucket vs sliding window is the easy part. The real interview is what happens when the limiter runs on fifty machines: where the counter lives, why 'local counters' quietly lets 50× your limit through, and how to enforce one global cap without a round-trip on every request.

Asked at Stripe, Cloudflare, GitHub +2

Aug 9, 2026·17 min read