We built lessons where the picture updates as you go. Click through, watch the stack grow.
URL Shortener, Twitter, Uber, Yelp, and more. Ten interactive lessons, two free to start.
Built for engineers prepping for interviews and anyone who wants the picture to match the story.
Big systems stop feeling like a black box
Interview prep, day job, or plain curiosity: same deal. You move through real architectures in order, with a 3D scene that matches the story instead of fighting it.
Built for system design interview prep and for engineers who want a clear mental model of distributed systems (caching, load balancing, sharding, queues, and more).
You see the build, not only the final slide
Boxes and arrows on a slide are fine until you need to feel how traffic moves. Here the diagram moves.
Each screen adds a piece. No wall of text before you see what changed.
You get the tradeoffs and the order we built things in, not a finished picture with no path.
Old proverb: teach someone to fish. Here you watch the pond, the net, and the stove in order.
The goal is a way of thinking you can take to the next problem, not a single canned diagram.
Every lesson runs in the browser: pick 3D or a flat whiteboard, move forward with the keyboard or buttons, and pick up where you left off once you sign in. Nothing to install.
You are not memorizing one diagram. You are watching how requests move, where data lives, and what breaks first when load spikes, so the same habits transfer when the interview question changes.
“What I cannot create, I do not understand.” — Richard Feynman. Same idea: read the step, then watch the scene catch up.
Text explains the move; the canvas shows it. You are not guessing which arrow meant what.
Nodes show up in order. Requests crawl along the lines. When something gets hot or slow, you see that too. Less guessing what the slide was trying to say.
Get notified when new lessons ship
New lesson announcements only. No product spam, no unrelated pitches. One email when something new goes live.
Open the lessons
Sign in, pick a topic, and your place saves across sessions.