Templates

Reference architectures, ready to simulate.

Each template is a complete, loadable diagram with traffic assumptions, scaling notes, and known bottlenecks. Open one to model, simulate, and review it as your own.

Links7 components

URL Shortener

Billions of redirects, a tiny write path.

A bit.ly-style service: a write-light, read-heavy system where short codes are generated once and resolved millions of times. The whole design hinges on absorbing redirect reads before they reach the database.

Open

Social11 components

Instagram Feed

Fan-out on write, read your timeline instantly.

A photo-sharing home feed. The hard part is timeline assembly: precompute feeds on write so the read path is a single cache lookup, while media is served from object storage via a CDN.

Open

Messaging10 components

WhatsApp Chat

Persistent connections, at-least-once delivery.

A real-time messaging backbone. Long-lived connections terminate at a gateway; messages flow through a durable queue so delivery survives offline recipients, with a store-and-forward worker doing the heavy lifting.

Open

Marketplace14 components

Food Delivery

Three-sided marketplace, real-time dispatch.

A DoorDash-style platform coordinating customers, restaurants, and couriers. Microservices own each domain; orders drive an async dispatch pipeline, and third-party maps/payments sit on the critical path.

Open

Storage12 components

File Storage

Upload once, serve from the edge, process async.

A Dropbox-style service. Large blobs land in object storage while a metadata DB tracks ownership and versions; thumbnails, virus scans, and indexing happen off the upload path via a queue.

Open

Search10 components

Search Engine

Query fast, index continuously, rank well.

A full-text search service. Queries hit an inverted index fronted by a cache, while a continuous indexing pipeline keeps documents fresh by consuming change events from the source of truth.

Open

Media11 components

Video Streaming

Transcode once, stream from the edge forever.

A YouTube/Netflix-style pipeline. Uploads are transcoded into multiple bitrates by a worker pool, stored once in an origin, and then served overwhelmingly from the CDN edge — the origin and app tier barely see playback traffic.

Open

Infra10 components

Notification System

One event in, many channels out — reliably.

A multi-channel notification platform. Producer events land on an event bus, get queued per channel, and are delivered by workers through push/email/SMS providers — with retries, rate limits, and observability baked in.

Open