Practice
Architecture Explorer
How real systems are put together. Click a component to see what it does, follow one request from the phone to the database and back, then open the whole thing in the Builder and see what breaks first.
- 50 systems
- 100 walk-throughs
- 444 components
- Every kind of component →
50 of 50 systems · 0 finished
- Streaming and media4
- NNetflixControl plane on AWS, video delivered from its own CDN.
- YYouTubeUpload, transcode, cache close to viewers.
- SSpotifyStreaming audio with a microservice backend.
- LLive sports at huge scaleTens of millions watching one match, scaled up beforehand.
- Messaging and social14
- WWhatsAppMillions of persistent connections per server.
- IInstagramA photo feed built on sharded databases and caches.
- XX (Twitter)Timelines built ahead of time, so reading is cheap.
- DDiscordMillions of live connections, and trillions of stored messages.
- SSlackReal-time messaging on top of sharded MySQL.
- FFacebookA graph of people and posts, cached in layers.
- LLinkedInThe home of Kafka, built around a professional graph.
- PPinterestSharded MySQL, with the shard written into every ID.
- RRedditVotes go through queues, and listings are precomputed.
- TTikTokAn endless feed, picked for you and prefetched.
- TTelegramCloud chats spread over data centers, with a custom protocol.
- ZZoomVideo is routed between participants, not mixed.
- TTwitchLive video in, many qualities out, chat alongside.
- TTinderRecommendations split by place, in real time.
- Commerce and payments9
- AAmazonServices and cells, built for availability.
- SShopifyThousands of shops, isolated into pods.
- SStripePayments you can retry without charging twice.
- CCard payments (Visa)Authorised in seconds, settled over the next days.
- UUPI (India)A shared switch between every bank and every app.
- AAirbnbSearch that ranks, and bookings that never double up.
- TTicket bookingA fair queue, then a short hold on your seats.
- SStock exchangeOne ordered sequence of orders, matched in memory.
- EE-commerce big saleA planned surge: cached browsing, queued buying.
- Mobility and delivery2
- UUberReal-time dispatch on a streaming backbone.
- DDoorDashThree apps, and a dispatcher matching them in real time.
- Storage and sync1
- DDropboxFiles split into blocks, so only what changed travels.
- Collaboration and apps4
- GGoogle DocsMany people typing in the same document at once.
- GGitHubA Rails app on top of replicated Git storage.
- FFigmaA design file as a live shared object.
- NNotionEverything is a block, sharded by workspace.
- Web and search5
- GGoogle SearchCrawl, index, then answer from many shards at once.
- GGoogle MapsTiles for looking, a graph for routing, phones for traffic.
- WWikipediaMostly cache hits, served from a small fleet.
- UURL shortenerA tiny key-value lookup with a very high read ratio.
- SSearch autocompleteSuggestions precomputed for every prefix.
- Infrastructure6
- CCloudflareThe same stack in every city, reached by anycast.
- AAmazon S3Objects spread over many disks, built to not lose any.
- KKubernetesA control loop that keeps reality equal to what you asked for.
- KKafka clusterA replicated, partitioned commit log.
- GGoogle SpannerA global SQL database that keeps clocks honest.
- EEmail delivery serviceAccept quickly, then send carefully, one provider at a time.
- AI and data2
- LLLM chat assistantA request queue in front of expensive GPUs.
- OOnline ad auctionA bidding auction that must finish in about 100 ms.
- Games and devices3
- MMultiplayer game backendFast authoritative servers, and slow services around them.
- IIoT platformMillions of small devices, each with an identity.
- VVoice assistantWake word on the device, understanding in the cloud.
10 components · 2 request walk-throughs
Netflix
Control plane on AWS, video delivered from its own CDN.
Click any box on the map to see what it does. A simplified model based on public talks and engineering write-ups. Real systems are larger and change over time.
Request walk-throughs
- Press play. What happens between pressing play and the first frame, and why the video itself never comes from AWS.
- A new title reaches viewers. How a master file becomes something a TV can stream from a box near the viewer.