Case /04 · 2026
Huusi
A Swiss learning platform for primary school, built to be trusted by parents and loved by kids. Seventy-five packages, thirteen picture-book stories, one warm system where feedback never says wrong.
Given
A learning tool only wins if a parent trusts it and a child comes back.
Parents pay, children use. The homepage had good substance and sold none of it, and the product was missing the moments that make a kid want the next exercise. An honest self-teardown set the brief.
- /aFive seconds to prove seriousness: Lehrplan 21, real schoolbooks, fair prices. And still warm enough that a child does not read it as a second shift of school.
- /bMultiple choice, cloze and sorting exist everywhere. The difference is the feedback, the tone, and what happens after a right answer.
- /cContent, design and code all hang on one person. Without hard automation, quality drops with the next fast commit.
- /dThe signature moments did not exist yet: a reward worth earning, a gentle way back after a mistake.
Proof
Warmth is a feature. The system runs on warm cream paper, a Fraunces and Nunito pairing, and a watercolour picture-book world. The load-bearing decision sits in three colours: mint means right, warm yellow means not yet, sky is a hint. Red is never an error signal. A child who is wrong sees no red cross, just a friendly way back. The reply reads «Richtig», not «Falsch».
/02
One dataset, four ways in.
Every package is usable digitally on a tablet, printed as a worksheet, as flashcards to quiz, and, where it fits, as a picture-book story to read aloud. One dataset, four ways into the child. The watercolour world of the stories, fine sepia lines and one saturated accent per scene, carries the brand where exercises alone would be too dry.
Thirteen picture-book stories, one illustration system.
/03
What runs underneath, and what CI checks on every commit
Next.js 16 on Supabase with row-level security, deployed on Vercel. Every commit runs through a wording check and a content check: sentence length, no leaked answers, no position bias in multiple choice. Content lives as code and ships itself: a seed pipeline pushes it to production after green CI. Progress saves with retry, so an outage never costs a star without a notice.
Fair by design: one-time purchases, no subscription, no stored card.
/04
Built for the tablet on the kitchen table.
Every screen is checked as rendered pixels on phone and tablet viewports. The screen has to hold still: a fix this cycle removed a flicker where answer options reshuffled on load and the exercise jumped under a reading child. Deterministic shuffling, identical on server and client, put it to rest.
Q.E.D.
- /01 Three feedback colours replace the red cross: mint right, yellow not yet, sky a hint.
- /02 From one dataset to four learning forms: tablet, print, flashcards, picture-book.
- /03 75 packages, 13 stories, 7 exercise types, all aligned to Lehrplan 21.
- /04 Fair by design: CHF 4.90 a package or CHF 39 a year, no subscription, no stored card.
- /05 Solo-built, held to team quality by wording and content gates, a seed pipeline, and a test suite.