Building an Offline-First Car Maintenance Tracker MVP with React Native & Expo

Introduction

Vehicle maintenance is predictable — yet easy to neglect. Oil changes, insurance renewals, inspections, fuel costs, and unexpected repairs quickly become fragmented across notes, receipts, and memory.

To solve this, we built Car Maintenance Tracker: an offline-first mobile MVP designed to centralize vehicle data, simplify logging, and provide clear spending insights — all without requiring an internet connection.

This article walks through the feature set, architectural decisions, and the technical foundation behind the app.

🚗 Core Features

Multi-Vehicle Management

Each vehicle profile stores structured, comprehensive data:

• Plate number, brand, model, year
• Fuel type (petrol, diesel, electric, hybrid, LPG)
• Odometer with km/mi support
• Insurance & inspection expiry dates
• Photo capture with compression

The detail screen combines a visual hero section with timeline-based event history and quick statistics for immediate context.

Event Logging System

The app supports four event categories:

• Maintenance (repairs, servicing, parts)
• Fuel
• Insurance
• Custom

Each event includes:

• Title and amount (auto-adjusted to selected currency)
• Date picker integration
• Mileage validation against current odometer
• Optional comments

Filtering by vehicle and category ensures fast access to relevant history.

Smart Reminder Engine

To prevent missed deadlines:

• Dual-date system (due date + reminder date)
• Recurring reminders with automatic regeneration
• Completion tracking with next-cycle creation
• Dashboard counters for pending vs. completed items

Recurring inspections and annual renewals are handled automatically.

Analytics Dashboard

Spending visualization is powered by react-native-gifted-charts:

• Donut chart by category
• 6-month animated trend bars
• Total, monthly average, and per-event metrics
• Per-vehicle filtering

The goal: actionable financial clarity at a glance.

Internationalization & Preferences

Designed for international use:

• English & Hungarian via react-i18next
• USD / EUR / HUF currency support
• Kilometer / Mile unit toggle

All preferences persist locally and update instantly.

🏗️ Architecture & Technical Decisions

Technology Stack

1️⃣ Offline-First with Migration Path

The app is structured around a DataService abstraction:

• LocalClient → AsyncStorage implementation
• RemoteClient → HTTP-ready backend placeholder

Switching from local-only to cloud sync requires minimal changes.
The UI remains untouched.

This enables:

• Fully offline functionality today
• Seamless backend integration tomorrow

2️⃣ Strong Type Safety

All domain entities (Car, CarEvent, Reminder, Preferences) are strictly typed.

This guarantees:

• Data consistency
• Safer refactoring
• Clear contracts between layers
• Reduced runtime errors

Strict TypeScript significantly improves long-term maintainability.

3️⃣ Separation of Concerns

The project structure enforces clean boundaries:

• Presentation layer → Expo Router screens
• Business logic → DataService
• Persistence layer → API clients
• Global state → Context providers
• Reusable UI → Shared components

The result is modular, testable, and extensible.

4️⃣ Business Logic Centralization

Smart behavior (e.g., mileage auto-update when logging fuel or maintenance) lives inside DataService, not in UI components.

This prevents duplication and keeps screens declarative.

5️⃣ Reusable Component Patterns

Common UX patterns are abstracted into shared components:

• Empty state layouts
• Card-based list items
• Modal form patterns
• Validation handling

Consistency improves both development speed and UX coherence.

📊 Implementation Highlights

Image Optimization

Vehicle photos are resized and compressed before being stored as base64 to reduce memory footprint while maintaining visual quality.

Mileage Integrity Validation

Events cannot reduce a vehicle’s recorded mileage, protecting historical accuracy.

Recurring Reminder Automation

When a recurring reminder is completed, the next cycle is generated automatically — no user action required.

🚀 Roadmap

Phase 2 — Cloud & Sync

• User authentication (Firebase / Supabase)
• Multi-device synchronization
• Export to PDF / CSV
• Shared vehicle access

Phase 3 — Intelligence

• Push notifications
• OCR receipt scanning
• Fuel efficiency tracking
• Predictive maintenance suggestions

Phase 4 — Ecosystem Integration

• Garage booking integrations
• Parts marketplace connectivity
• Insurance API sync
• Fuel price comparison

✅ Conclusion

This MVP demonstrates how a well-architected React Native application can deliver a polished, offline-first experience while remaining fully scalable.

Key strengths:

• Offline-first by design
• Clear abstraction layers
• Strict TypeScript typing
• Clean separation of responsibilities
• Ready-to-scale architecture

The foundation is production-ready, extensible, and future-proof.

Built with React Native, Expo, and TypeScript — engineered for the long road ahead.