kuroe

MEEDO

Water utility billing platform (Android + Web) for a local water district

• ▸Built an offline-first Android field app (Kotlin, Jetpack Compose, Hilt, Room, Firebase) letting meter readers record readings anywhere on route with no signal, print an itemized bill on the spot over a Bluetooth thermal printer, and sync automatically once back in coverage.
• ▸Implemented background sync via WorkManager as a network-constrained CoroutineWorker with exponential back-off (30s rising to a 5min cap) and per-reading PENDING/SYNCED/FAILED state, so a flaky connection degrades throughput instead of losing field data.
• ▸Encoded the district's board-approved rate card as a pure, unit-testable billing engine: per-classification minimum charges, a 10 cubic metre allowance with metered rate beyond it, a 15-day grace period, a recurring 3% delinquency surcharge, a once-per-delinquency fee, and projected overdue totals.
• ▸Built the admin console in Next.js 16 / React 19 / TypeScript on Firestore with security rules: concessionaire and connection records, billing runs, collections, Recharts reporting, team management, an audit trail, and an Excel importer to migrate the district off its existing billing spreadsheet.