Microsoft system design interview questions
5 questions on this site are reported in Microsoft 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, multi-channel, idempotency, rate-limiting, priority-queues, frontier, politeness, dedupe, scheduling, distributed-queues.
Attribution comes from public interview guides and candidate reports, not from Microsoft. 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 a Notification System
Deliver push, email, SMS and in-app notifications to hundreds of millions of users: the right channel, once, on time, and never at 3 a.m.
How to prepare for a Microsoft 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 Microsoft interviews under different names.
- Design a Payment Systemconsistency · idempotency · ledger
- Design a News Feedfan-out · ranking · caching
- Design Google Mapsgeospatial · routing · graphs
- Design a Matchmaking Systemqueues · scheduling · latency
- Design Ubergeospatial · matching · streaming
- Design a Rate Limiteralgorithms · counters · redis