A mobile-first classroom attendance app that lets a teacher mark Present/Absent in one tap per student and auto-produces the boys/girls-split daily, weekly, monthly and yearly summaries their school requires.
Attendify replaces a teacher's paper register. The Expo/React Native app captures attendance in one tap per student on a date-navigated list, and a NestJS + PostgreSQL backend computes the gender-split daily, weekly, monthly and yearly summaries the school needs — on demand, instead of a manual month-end re-count.
Solo, end-to-end build (NestJS backend + Expo/React Native mobile, design through EAS release) for a specific schoolteacher whose paper register was slow to fill and slower to re-tally into the gender-split per-division reports the school expects monthly. Scope: data model, REST API, auth, mobile UI, state management, and internal APK distribution.
The teacher marked a paper register daily, then at month-end manually re-counted Present days, split by gender, per class/division for school reports. That re-tally is error-prone, not reusable, and impossible to audit. The app needed one-tap-per-student capture and school-format summaries on demand.
ChallengeSchool reports demand boys/girls splits at four granularities (daily, weekly, monthly, yearly), and the academic 'week' is week-within-the-month (1-5), not ISO week — naive per-endpoint SQL would be four near-duplicate queries disagreeing on edge cases.
FixCentralised the maths in the attendance service: fetch the marks for the date range once, then group in-memory by a custom week-of-month function and by gender. One source of truth feeds all summary endpoints with render-ready totals.
ChallengeOn Android cold start, the login screen flashed before redux-persist rehydrated the saved JWT.
FixWrapped the app in PersistGate (whitelist: auth) and gated the entry route on the rehydrated accessToken before choosing login vs class-select; auth routes also suppress the bottom-tab layout.