System design, executed

Your design,
under load.

Wire up components, push a thousand requests a second through them, and read exactly what each one did. No slides, no hand-waving.

Run the first lesson Open the canvas

free · start without an account · sign in to keep your work

Cache. Shard. Queue.Concept illustration

The learning loop

  1. 01

    Build it.

    Connect the components. Make a decision.

  2. 02

    Run it.

    Send requests through your design.

  3. 03

    Understand it.

    See what failed. Change one thing. Repeat.

Start with one real problem

Fast is easy.
Fast and correct?

A popular recipe keeps hitting the database. Add a cache, then find out what happens when the language changes or an ingredient gets corrected.

01 / 05

Same recipe. Another database read?

Without a cache, both visits ask the database for the same recipe. That repeated work is your starting problem.

The starting pointIllustrated preview
Visitor
Service
Database
Cache key examplerecipe:42
Repeated work01

Both visits reach the database.

One guided lesson. Five decisions.
Each stage tests the design you actually build.

Run the first lesson

Your architecture.
A blank canvas.

Have a system in mind? Start from scratch or pick a template. Keep your focus on the design while the editor handles the connections.

  • Connect, reconnect and shape your routes.
  • Group components and tidy the layout.
  • Save locally. Export editable diagrams.
Open the canvas

Go beyond the guided lesson

What changes under load?

Bring more traffic. Adjust your design. Compare the results in the open traffic lab.

Try the traffic lab

A few things
before you start.

Can I start without an account?

Yes. Open a lesson or a blank canvas and start building. No signup is required.

Will my work be saved?

Yes. Signed in, your diagrams and lesson progress are saved to your account and open on any device. As a guest, your draft and progress stay in this browser, and clearing browser data removes them. Export important diagrams as editable JSON for your own backup.

Is this a real production simulation?

It is a teaching model that runs against your diagram. It helps you see requests, cache behavior and bottlenecks under defined assumptions. Results are not cloud benchmarks or production capacity estimates.

What can I use today?

A complete guided caching lesson, an open traffic lab and a standalone diagram editor. Start with the lesson for guidance, or open the canvas to draw your own architecture.

Make your first
design decision.

Run the first lesson

Free to start. No setup. No signup.