sdlc.dev

Design walkthroughs

Patterns, companies and the systems we build, one narrated diagram at a time.

New12:09
Developer tools · beginnerSDLC.dev: from idea to specification

How dd-sdlc-ai turns a product idea into specification documents.

New13:44
Social · intermediateDiscord chat

One Elixir process per server, relays for fan-out, Rust data services and trillions of messages on ScyllaDB.

New13:44
Streaming · intermediateNetflix streaming

A control plane in AWS steers every play to Open Connect servers inside your ISP.

New13:07
Payments · intermediateStripe payments

From API call to settled payment: idempotency keys, rate limiters, 3-D Secure and signed webhooks.

New8:39
Mobility · intermediateUber rides: from request to live trip

From ride request to live trip: H3 dispatch, upfront pricing, live tracking.

New13:03
Messaging · intermediateWhatsApp messaging

Store and forward for billions: Erlang chat servers, offline queues, and Signal encryption on every device.

New13:45
Streaming · intermediateYouTube video

From upload to play: resumable uploads, transcoding on custom chips, Vitess-sharded metadata and video served from caches inside your ISP.