Design YouTube

Advanced75 minBuilds Video StreamingRead first: 13.1 Object storage, 13.2 Uploads and processing, 13.3 CDNs and media delivery

STEP 1 OF 13

The brief

You are designing a video platform like YouTube. Creators upload videos, from short clips to multi-hour streams recorded at 4K. Viewers press play and expect the video to start within a second or two and keep playing smoothly on anything from fiber to a train's patchy 4G.

This lab designs one region's video service at numbers you can load test.

How big it is

Playback requests (manifests and video segments): 20,000 / second at peak
Uploads and other writes: 100 / second
Average upload: about 1 GB
p99 goal for API and origin requests: under 200 ms

What makes video different

Files are huge. A gigabyte can't go through an application server, or be uploaded in one fragile request.
Processing is slow. Transcoding an hour of 4K takes many CPU-minutes, so it must happen asynchronously.
Playback is about bytes, not requests. A popular video is fetched by millions of people, which is a job for a CDN, not your servers.

All changes saved

0 components · 0 connections

A blank canvas. A better system.

Add components from the palette, then drag between them to connect the request and event flow.

React Flow