One student built it.
I'm a student. I got tired of math classes that hand you a formula and tell you to memorize it — the interesting part, why the formula has to be the shape it is, kept getting skipped. So I went looking for it on my own, problem by problem.
What worked was small. Predict what comes next before you read it. Derive the formula instead of memorizing it. And — the part I kept coming back to — try to teach it back, out loud, as if no one had ever seen it before. The cracks in your own understanding show up in the first thirty seconds.
Build Understanding is that loop, automated. Twelve courses, hundreds of topics, three modes — read, build, teach. None of it works if you only want to memorize. All of it works if you actually want to learn.
The whole thing is built by one person: I author the curriculum, design the screens, write the code, and tune the AI graders. That's not a flex — it's the point. The product stays one coherent opinion about how math should be learned, held all the way through.
Away from the laptop, I tutor students in person — nothing exposes a fuzzy explanation faster than a real student watching you give it — and I get into the mountains whenever I can. The photo below is the other half of the office.
Three rules. That's all there is.
The product is opinionated — every screen is built around these. If you can do all three, you understand the topic.
Construct, don't memorize
Every topic opens by deriving the result from something you already trust — not by handing you a formula to memorize. Memory comes second, after the reasoning is yours.
See it move
Most topics include a Build It that lets you drag the inputs and watch the equation respond. Concepts that lived as static formulas in a textbook become dynamic objects you can poke.
Teach it back
A curious AI student asks naïve questions. Hand-waving fails immediately. The Clarity score doesn't grade your answer — it grades whether you actually understood what you said.
Small team. Big catalogue.
None of this is solo work.
Cyndi Lui
Calculus teacherThe most inspiring teacher I've had. Showed me calculus isn't a set of rules to memorize — it's a way of seeing the world. Her passion for teaching is the reason this app exists.
Ms. Holly
Geometry teacher · mentorBelieved in me early on when math wasn't clicking, and helped me almost every day until it did. The right mentor changes everything.
Early test users
Etienne, Clea, Christoph, Aren, Wyett, AaronFirst people to use Build Understanding and tell me what was broken. Patient with the bugs, honest with the critiques. The product is sharper for it.