archreview.dev
Practise system design on problems that have numbers.
Yes: it is a canvas for drawing boxes and arrows. The difference is what happens when you press Check. Claude reads the design against the requirements of the task — a vendor that answers in three to seven minutes, two hundred seats and five thousand buyers — scores it on five axes, and pins what is missing to the components it is missing from. Every box the requirements never asked for costs you.
Free, no account, nothing to install.
Three ways in, depending on where you are
- never done this
Learn
Short lessons on the mechanisms a design is judged by — why a load balancer does not survive a restart on its own, what a queue actually promises. Each one ends on the canvas with something to fix.
- want the practice
Tasks
Concrete situations with numbers in them: a vendor that answers in three to seven minutes, two hundred seats and five thousand buyers. Build the topology, get it read against the requirements.
- have a real problem
Your own design
Describe what you are actually building, draw it, and have that reviewed instead. Your brief, your requirements, the same five axes.
Try one connection, right here
This is the real canvas, and the check below is real code reading what you drew — the same two halves as everything else on the site, at their smallest.
Your turn. Drag from a dot on the edge of the web client to a dot on the load balancer, so the two are connected. Then press Check.
What it costs
Everything here is free and needs no account: the lessons, the tasks, the canvas, and a review of what you draw. The one thing that is not free is the long version of that review — and it is not paid to us.
- Free, no account
Five scores, a sentence and one next step, on this site’s shared key. Enough to know where a design stands and what to change next.
- Full review, your own key
Sign in, paste an Anthropic API key, and the same reviews come back with findings written against specific components — billed to your account by Anthropic, a few cents a go. Nothing is charged here.
The long one looks like this:
A correct, minimal fan-out that meets all three requirements, weakened only by an empty health-check property that leaves failover unspecified.
- requirements9does what was asked, end to end
- resilience5single points of failure, retries, dead dependencies
- scale9holds the stated load; where it breaks first
- data8storage and consistency against the requirements
- simplicity10can a small team run this; is anything here for nothing
Every finding names the components it concerns, and the canvas highlights them.