Google system design interview questions
6 questions on this site are reported in Google software engineer interviews. Each is a guided run through requirements, back-of-envelope numbers, an interactive design, user flows and deep dives with interviewer follow-ups. Patterns covered: key-generation, caching, cdn, analytics, real-time, websockets, fan-out, chat, transcoding, adaptive-bitrate, pipelines, storage, geospatial, routing, graphs, frontier, politeness, dedupe, scheduling, distributed-queues, algorithms, counters, redis, edge.
Attribution comes from public interview guides and candidate reports, not from Google. It indicates where a question has been asked, nothing more.
Design a URL Shortener
bit.ly at scale: turn long URLs into short codes, redirect in milliseconds from anywhere, count the clicks.
Design Slack
Real-time team messaging: channels, DMs, presence, history and search for millions of concurrent users.
Design YouTube
Upload, transcode, and stream video to a billion viewers: a processing pipeline on one side, a CDN problem on the other.
Design Google Maps
Map tiles, place search, turn-by-turn routing with live traffic, and ETAs for a billion users.
Design a Web Crawler
Fetch billions of pages a month politely, discover new links, skip duplicates, and keep the copy fresh without getting the crawler banned.
How to prepare for a Google system design interview
Large-company loops run 45 to 60 minutes, expect numbers, and spend most of the time on deep dives. Work each question above in practice mode until you can produce the requirements, the estimates and the flows without looking, then read the interview framework guide for how to structure the hour. The other questions on the site teach patterns that show up in Google interviews under different names.
- Design a Payment Systemconsistency · idempotency · ledger
- Design a News Feedfan-out · ranking · caching
- Design a Matchmaking Systemqueues · scheduling · latency
- Design Ubergeospatial · matching · streaming
- Design a Notification Systemfan-out · multi-channel · idempotency