Cabelo em Dia — Tracking for people treating hair loss with a doctor

The limit was written before the code. No screen, text, email or notification suggests, calculates or adjusts a dose, and there is no milligram selector: the treatment is registered by category and in free text, as the doctor prescribed it. There is also no promise of results, no diagnosis and no AI analysis of photos. An automated test scans the texts for forbidden words, and reminders swap the name a person typed for a generic label if it matches a medication name, because the notification shows on the lock screen.

A progress photo is only useful if it is taken under the same conditions. The camera shows the angle's silhouette, the previous session's photo as an overlay to repeat the position, and a light meter. On the server, each photo is rewritten without metadata (location, camera data) and encrypted with AES-256-GCM, with a per-person key derived from a master key. Only the owner can access it, and the app neither edits the image nor judges the result: the doctor does.

When the person logs an effect, the app answers on three levels: watch, talk to the doctor soon, or seek care now, with an emergency screen for serious signs. The text says what it usually is, what to do and when to see the doctor, and each piece of guidance cites its source. The logic is pure and covered by tests, and what the person logs goes into the report for the appointment.

The app only opens after health consent, and the person can export all their data or delete the account from Profile. Login is by email, with no password, and the server stores only the hash (HMAC) of the code, the link and the session, never the value itself. Since an app installed on the home screen cannot see the browser's storage, the onboarding step is also saved on the server, so the person resumes where they left off.