PriceDelta

Automated Retail Intelligence Engine

PriceDelta is a full-stack market intelligence platform that automates retail price tracking, ingesting high-frequency product data, visualizing historical market trends, and execututing real-time alert triggers when prices fluctuate beyond user-defined thresholds.

✨ Key Features

🛒 Intelligent Tracking

• Automated Scraper Engine: Background workers (ingestor.ts) autonomously scrape and normalize product data from external sources.
• Trend Analytics: Interactive visualization of historical price action using Recharts, helping users identify optimal buying windows.
• Smart Alerts: User-defined custom price targets, with distinct alertChecker jobs to trigger instant email notifications when targets are met.

🛡️ Secure & Scalable Implementation

• Robust Authentication: Stateless JWT-based auth flow with secure session management and Bcrypt password hashing.
• End-to-End Type Safety: Strict type sharing between the Prisma database schema and React frontend ensures runtime reliability.
• Performance Optimization: Uses optimistic UI updates and responsive design with Tailwind CSS.

⚙️ System Architecture & Data Pipeline

🏗️ Modular Backend Design

• Decoupled Microservices: Utilizes a Controller-Service pattern in Express.js to strictly separate business logic from API orchestration.

• Data Integrity: Leverages Prisma ORM with PostgreSQL to enforce strict schema definitions across complex User, Product, and PriceHistory relations.

🔄 Automated Monitoring Workflow

• Ingestion Engine: Built a dedicated worker that fetches raw external data, normalizes it to the internal schema, and upserts it into persistent storage.

• Scheduled Execution: Integrated node-cron to orchestrate recurring "Price Check" jobs that detect market fluctuations at defined intervals.

• Async Notification Logic: Developed an independent service that evaluates price changes against watchlists, dispatching email alerts via Nodemailer only when specific thresholds are met.

🚀 Tech Stack

Frontend

• React (Vite): & TypeScript: Modular architecture with strict end-to-end type safety.
• Tailwind CSS: Responsive, high-performance styling.
• Axios: Configured with interceptors to handle authenticated API requests and global error management.
• Recharts: Interactive data visualization for historical price trends.

Backend

• Node.js & Express.js: Built a high-concurrency RESTful API using a modular architecture for efficient request handling.
• Prisma ORM: & PostgreSQL: Type-safe ORM with strict relational schema enforcement and automated migrations.
• JSON Web Tokens (JWT): & Bcrypt.js: Stateless authentication with industry-standard secure password hashing.
• Nodemailer: & Node-Cron: Orchestrates background ingestion workers and automated SMTP communication for email alert dispatch.

🛠️ Setup & Installation

Prerequisites

• Node.js (v18 or higher recommended)
• PostgreSQL database instance

Backend

1. Navigate to the server directory:

   cd backend
   npm install

2. Configure environment variables:
   • Create a .env file matching .env.example.
   • Ensure your PostgreSQL instance is running.
3. Initialize the database:

   npx prisma migrate dev --name init

4. Start the server:

   npm run dev

Frontend

1. Navigate to the client directory:

   cd frontend
   npm install

2. Start the development server:

   npm run dev

---

API Endpoints Overview

• POST /api/auth/register: Register a new user.
• POST /api/auth/login: Log in a user.
• GET /api/user/me: Get authenticated user's profile.
• PATCH /api/user/me: Update authenticated user's profile.
• GET /api/products: Get all products.
• GET /api/products/:id: Get a single product with price history.
• GET /api/alerts: Get all price alerts for the authenticated user.
• POST /api/alerts: Create a new price alert.
• DELETE /api/alerts/:id: Delete a price alert.
• GET /api/notifications: Get all notifications for the authenticated user.
• PATCH /api/notifications/:id/read: Mark a notification as read.
• GET /health: Health check endpoint.
• GET /api/ingest: Manually trigger data ingestion.

Folder Structure (Simplified)

.
├── backend/
│   ├── .gitignore
│   ├── nodemon.json
│   ├── package-lock.json
│   ├── package.json
│   ├── tsconfig.json
│   ├── generated/           # Generated Prisma client files
│   ├── node_modules/        # Project dependencies
│   ├── prisma/              # Prisma schema, migrations
│   └── src/
│       ├── config/          # Application configuration
│       ├── controllers/     # Request handlers
│       ├── generated/       # Prisma client and model definitions
│       ├── middleware/      # Express middleware
│       ├── routes/          # API route definitions
│       ├── workers/         # Background worker logic
│       └── index.ts         # Backend entry point
├── frontend/
│   ├── .gitignore
│   ├── dev.js
│   ├── eslint.config.js
│   ├── index.html
│   ├── package-lock.json
│   ├── package.json
│   ├── tailwind.config.js
│   ├── tsconfig.app.json
│   ├── tsconfig.json
│   ├── tsconfig.node.json
│   ├── vite.config.ts
│   ├── node_modules/        # Project dependencies
│   ├── public/              # Static assets
│   └── src/
│       ├── App.css
│       ├── App.tsx
│       ├── index.css
│       ├── main.tsx         # Frontend entry point
│       ├── api/             # API client services
│       ├── assets/          # Images and other static files
│       ├── components/      # Reusable UI components
│       ├── contexts/        # React Context providers
│       ├── hooks/           # Custom React hooks
│       ├── pages/           # Page-level components
│       ├── services/        # Frontend business logic services
│       ├── types/           # TypeScript type definitions
│       └── utils/           # Utility functions
└── README.md