Every idea is a diagramWatch it grow, one tradeoff at a time.
Short lessons with diagrams you can step through. Start with a simple design, find where it hurts, and fix it one tradeoff at a time.
Swipe sideways to pan · drag a box to move it
Begin with the why
Clarify requirements, estimate scale, and identify the real constraint before drawing boxes.
Learn what each part costs
Explore databases, caches, queues, replication, and the tradeoffs behind each choice.
Put the ideas to work
Follow real product designs from their first requirement to a system that can grow.
LEARN BY EXAMPLE
Follow a design all the way through.
Each case starts with a product problem, then adds only the components the design actually needs.
Storage and scale
URL shortener
Handle billions of redirects without making writes complicated.
Data lifecycle
Pastebin
Store, retrieve, and expire shared text without overbuilding.
Traffic control
Rate limiter
Set fair request limits and make the decision quickly.
Search and latency
Typeahead
Return useful suggestions before a query is complete.
Realtime systems
Messaging
Deliver messages in order, even when a device goes offline.
Distributed data
File sync
Keep devices in sync and transfer only what changed.
Distributed storage
Dynamo
Explore the choices behind an available key-value store.
Event streaming
Kafka
Understand durable, ordered logs and replayable events.
Don't take my word for it. Tell the internet.
Learned something on Blueprint that finally clicked? Don't just close the tab. Tag me on X and say it your way: a meme, a rant, a one-line roast of load balancers. I read every single one.
A good place to start is the beginning.
Get the interview framework, estimation basics, and a first-principles view of system design.
Want a simulator to experiment with? Breakscale is one of the best.