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Delivery & Build

Local-First Mobile Finance App

I designed and delivered a production-ready mobile app that operates entirely offline, handling structured financial data without servers, accounts, or network dependency.

Platform
iOS / Android
Architecture
Local-First / Offline
Role
Architect & Developer
Delivery Mode
Solo end-to-end
Background

Context

This project was built as a production-ready mobile application to validate and demonstrate delivery of a local-first, offline-capable system handling structured financial data.

The goal was to design and ship a mobile app that works without servers, accounts, or network dependency, while still providing analytics, data integrity, and export capabilities. The project serves as a concrete example of how I approach mobile system design.

What wasn't working

Problem

Many mobile apps assume constant connectivity and backend infrastructure, which creates fragility for field users or privacy-sensitive use cases.

Managing structured financial data entirely on-device

Supporting multiple currencies with deterministic conversion

Providing meaningful analytics without backend processing

Ensuring data persistence, consistency, and exportability

Shipping a real, installable mobile application end-to-end

How I led delivery

Approach

I treated the app as a small but complete system, not a UI exercise. The design focused on clear separation between data access, business logic, and UI. Complexity was kept in the system design, not pushed onto the user.

Key decisions

  • Repository pattern for predictable, testable data handling
  • Explicit currency conversion logic—no hidden external dependencies
  • Analytics computed locally—works without connectivity
  • Production build pipeline from day one—real deployments, not prototypes
  • Scope discipline—ship a coherent system, defer non-essential features
What I built

Solution

What I built

A local-first mobile application that operates entirely offline, handling structured financial data without servers, accounts, or network dependency.

Income & expense tracking
Multi-currency support
Local analytics & dashboards
Category breakdowns
Historical trends
CSV export via native sharing
Full offline operation
Local data persistence

How it works

Data Layer

Repository pattern with local database—structured storage, deterministic calculations, full persistence without network calls.

Analytics Engine

Currency conversion and aggregation computed on-device—dashboards, category breakdowns, trends all generated locally.

Export & Sharing

CSV export via native mobile sharing—data portability without server dependencies or vendor lock-in.

Technology

Tech Stack

Mobile Framework

  • React Native
  • TypeScript
  • Expo (managed workflow)

Data & State

  • SQLite (local database)
  • Zustand (state management)
  • Repository pattern

Deployment

  • iOS App Store
  • Android (production builds)
  • EAS Build pipeline
The shift

Before vs After

Traditional Mobile Apps

  • Require backend infrastructure
  • Depend on network connectivity
  • User accounts & authentication
  • Server-side analytics processing
  • Vendor lock-in for data
  • Network latency affects UX

Local-First Approach

  • Zero backend dependency
  • Fully offline operation
  • No accounts needed
  • On-device analytics
  • User owns all data
  • Instant, responsive UX
Why this matters

What this proves

You get production-quality mobile apps, not demos or prototypes

You get offline-first systems that work in field conditions without network dependency

You get complete mobile delivery—from architecture through app store deployment

You get reusable patterns for internal tools, field apps, or companion mobile systems

If you need mobile apps for field operations, internal tools, or offline-capable systems—I can help you deliver production-ready mobile solutions alongside your backend infrastructure.

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