📦 Last Mile Food Delivery Optimization App

Author: Amar Kumar
Submission Date: [2025-05-09]
Assignment: LE Hiring - Final Technical Assignment
Duration: 2 Days

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🚀 Overview

This app is designed to help a single delivery driver optimize the delivery of 5–6 food orders while considering real-world constraints like perishability (e.g., ice cream), priority, and deadlines. The system includes:

• 🌐 A cloud-deployed REST API (Render)
• 📱 A mobile app built with React Native + Expo
• 📊 Algorithmic prioritization of routes
• 🗂️ Documentation + diagrams + deployment ready

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📚 Table of Contents

• Features
• Architecture
• Backend
• Mobile App
• Data
• Route Optimization
• Deployment
• Screenshots
• Assumptions
• UML & Diagrams
• How to Run
• Future Improvements

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✅ Features

Module	Functionality
📦 Order Intake	Accepts new orders with location, priority, deadline, type
📍 Route Engine	Optimizes based on distance, priority, perishability using Google API
🚗 Driver App	Driver can accept/reject orders, see routes and mark deliveries as complete
📊 History View	Visual dashboard for completed deliveries with metrics
🔐 Auth Light	Drivers login using email; ID is stored in AsyncStorage
☁️ Cloud Deployment	All APIs are deployed on Render

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🧱 Architecture

[React Native App]
     |
     | REST API calls
     v
[Express.js Backend (Render)]
     |
     | -> MongoDB Atlas
     | -> Google Maps Distance Matrix API

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⚙️ Backend

• Framework: Node.js + Express
• Database: MongoDB Atlas
• Routes:
  • POST /api/orders — Add order
  • POST /api/driver/:id/active-route — Get prioritized orders
  • POST /api/order/:id/complete — Mark as delivered
  • POST /api/order/:id/reject — Cancel/release order
  • GET /api/driver/:id/history — View delivery history
• Priority Factors:
  • Order priority
  • Delivery deadlines
  • Perishable items (ice cream)
  • Distance from driver

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📱 Mobile App

Built using React Native + Expo with Tailwind CSS for styling.

Screens:

• Login — Set driver ID via email
• Home — View 5 prioritized orders
• Active Orders — Map + "Mark as Delivered"
• History — Past deliveries + metrics
• Logout — Clear AsyncStorage and redirect

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⚡ Performance & Reliability

🧠 Smart Caching (React Native)

• Used AsyncStorage to cache driver ID and accepted orders
• Reduces unnecessary API calls on each screen load
• Cached data is auto-cleared on logout

🌐 Network Handling

• Optimized with Axios interceptors and error boundaries
• Graceful fallback when offline (displays cached orders)
• Loading indicators and error alerts shown for network failures

📲 Implementation Highlights

• Cached previously fetched delivery routes to reduce Google Maps API calls
• Revalidates fresh data using useFocusEffect on tab switch
• Handles edge cases like:
  • API down → fallback to local storage
  • Location permission denied → warning shown

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📊 Route Optimization

Inputs:

• Driver's current GPS location (via Expo Location)
• Customer lat/long
• Google Distance Matrix

Logic:

1. Filter high-priority and perishable items
2. Use Google API to get durations/distances
3. Sort top 5 based on:
   • Priority
   • Shortest ETA
   • Product type weight (ice cream > pizza)

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📦 Dataset

Used a simulated dataset of 30 orders, based on schema:

order_id	product_type	delivery_priority	customer_lat	customer_long	delivery_deadline
1001	Ice Cream	High	28.6139	77.209	2025-01-01T12:00Z

(Stored in MongoDB via .json import)

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🌐 Deployment

• 🔗 Render Backend: https://food-delivery-optimization.onrender.com
• 🔐 Environment Variables:
  • GOOGLE_API_KEY
  • MONGO_URI

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📷 Screenshots

Here are some screenshots showcasing the app's functionality:

• 🏠 Home Page
  

• 🗺️ Registration/Login Page
  

• 📊 Active Order Page
  

• ✅ Driver Order History Page
  

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📝 Assumptions

• Each order belongs to a single driver
• Driver can cancel only before accepting
• Prioritization logic prefers perishable and urgent items
• Routes fetched only on tab focus for speed

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🔄 How to Run

Backend:

npm install
npm run dev

Mobile:

cd mobile-app
npx expo start

📦 Mobile App Download

You can download and test the mobile APK here:

👉 Download APK

Built using Expo + React Native. Tested on Android 10+.

Update .env or constants.js with your backend base URL.

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📷 UML Diagram

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🚀 Future Improvements

• Add Firebase/Auth0 login with roles
• Polyline route map between orders
• Admin dashboard for viewing all orders
• Driver performance leaderboard