Aljohn Arranguez

I build production systems for paying clients, from proposal and requirements gathering through deployment, documentation, and staff training. My work helps utilities, retailers, and service businesses keep operating reliably, including when internet connectivity fails.

For MEEDO, a local water district’s billing platform, I built an offline-first Kotlin Android app for meter readers and a Next.js admin console. The app prints itemized bills over Bluetooth, syncs readings automatically after reconnecting, and protects field data with retry logic and per-reading sync states.

I also built InvenTrack, a point-of-sale and inventory platform using Angular, TypeScript, Supabase, and PostgreSQL. It supports batch and expiry tracking, reorder forecasting, procurement workflows, row-level security, and offline transaction processing for cashiers.

Alongside client systems, I built LiCEnSURE, a machine-learning decision-support tool that forecasts licensure exam outcomes with 86.12% accuracy and explainable predictions. I work across TypeScript, React, Next.js, Angular, Kotlin, Jetpack Compose, Firebase, Supabase, PostgreSQL, and FastAPI.