📈 Stock Exchange

A simplified Stock Exchange Simulation built to understand how trades are executed, orders are matched, and prices are updated in real time.

This project implements the core concepts of an exchange using an order-matching engine, Redis queues, and real-time WebSocket updates.

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🚀 Features

• Order Placement – Place buy/sell orders via REST API (POST /api/v1/order).
• Order Matching Engine – Matches incoming orders using price-time priority.
• Trade Execution – Generates trade events with executed price and quantity.
• Real-Time Market Data – WebSocket streams for trades, ticker, and market depth.
• Redis Pub/Sub & Queues – Used for decoupling API, Engine, and Database layers.
• Time Series Database – Stores executed trades for historical price data.

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🏗️ Architecture

The flow of the system:

1. Browser (Client)

   • Sends new orders via REST API.
   • Subscribes to WebSocket for live updates.

2. API Service

   • Accepts incoming orders (POST /api/v1/order).
   • Pushes orders into a Redis queue for processing.

3. Matching Engine

   • Consumes orders from the queue.
   • Matches orders (buy vs sell).
   • Publishes trade events (executed quantity, price).

4. Redis Pub/Sub & Queues

   • Broadcasts trade, ticker, and depth updates.
   • Decouples services for scalability.

5. Database Processor

   • Reads executed trades from queue.
   • Stores them into a Time-Series Database (price, timestamp).

6. WebSocket Service

   • Pushes live updates to clients (trades, ticker, depth).

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⚙️ Tech Stack

• Backend: Node.js / TypeScript
• Data Store: Redis (Pub/Sub + Queues)
• Database: Time-Series DB (TimescaleDB)
• Frontend: Nextjs (Order Book UI, Charts)
• Transport: REST API + WebSocket