TradeTrac — Distributed Trading Platform

A production-grade distributed system built with .NET 8, demonstrating lead-level architecture decisions across three microservices.

Clone it. Run one command. See a real distributed system.

git clone https://github.com/padmarajan26/TradeTrac.git
cd TradeTrac
docker-compose up --build

---

Architecture

┌─────────────────────────────────────────────────────────┐
│              API Gateway  (YARP Reverse Proxy)          │
│                    JWT Auth · Routing                   │
└──────────────────┬──────────────────────────────────────┘
                   │
       ┌───────────▼──────────┐
       │    Order Service     │
       │  .NET 8 Clean Arch   │
       │  DDD · CQRS · EF Core│
       └───────────┬──────────┘
                   │ publishes events
       ┌───────────▼──────────┐
       │      RabbitMQ        │
       │    (MassTransit)     │
       └───────────┬──────────┘
                   │ consumes events
       ┌───────────▼──────────┐
       │ Notification Service │
       │ Hangfire · Idempotent│
       │  consumer · Retry    │
       └──────────────────────┘

PostgreSQL (Orders)    PostgreSQL (Notifications)
OpenTelemetry → Jaeger + Prometheus

---

Tech Stack

Concern	Technology
Language	C# / .NET 8
Architecture	Clean Architecture + DDD + CQRS
ORM	EF Core 8 + Dapper (read side)
Message bus	RabbitMQ via MassTransit
Background jobs	Hangfire (PostgreSQL backed)
API Gateway	YARP reverse proxy
Auth	JWT Bearer
Observability	OpenTelemetry → Jaeger + Prometheus
Containerisation	Docker + Docker Compose
CI/CD	GitHub Actions

---

Quick Start

Prerequisites: Docker Desktop

git clone https://github.com/padmarajan26/TradeTrac.git
cd TradeTrac
docker-compose up --build

Service	URL
Order Service Swagger	http://localhost:5001/swagger
Hangfire Dashboard	http://localhost:5002/hangfire
RabbitMQ Management	http://localhost:15672
Jaeger Traces	http://localhost:16686
Prometheus Metrics	http://localhost:9090

---

Try It

1. Get a token

POST http://localhost:5001/auth/token
{ "username": "trader1", "password": "Password123!" }

2. Place an order

POST http://localhost:5001/api/orders
Authorization: Bearer <token>
{
  "symbol": "INFY",
  "side": "Buy",
  "orderType": "Limit",
  "price": 1800.50,
  "quantity": 10,
  "currency": "INR"
}

3. Watch the event flow

• Order saved to PostgreSQL
• OrderPlacedIntegrationEvent published to RabbitMQ (via Outbox pattern)
• Notification Service consumes the event (idempotent)
• Hangfire job fires → notification logged
• Full trace visible in Jaeger

---

Architecture Decisions

Outbox Pattern

Domain events are written to the outbox_messages table in the same transaction as the order. A background worker publishes them to RabbitMQ. This guarantees no event is lost even if the broker is temporarily unavailable.

CQRS with Dapper on the Read Side

Commands go through EF Core (full aggregate loading, domain event dispatch). Queries use raw Dapper — no EF overhead, direct SQL, easily optimised with indexes.

Idempotent Consumers

Every RabbitMQ message is checked against a processed_events table before processing. Re-delivered messages are safely ignored.

Clean Architecture

Domain           → no dependencies (pure business logic)
Application      → depends on Domain (CQRS handlers, MediatR)
Infrastructure   → depends on Application (EF Core, RabbitMQ)
API              → depends on Application (controllers, middleware)

---

Project Structure

TradeTrac/
├── src/
│   ├── OrderService/
│   │   ├── Domain/          # Entities, Value Objects, Domain Events
│   │   ├── Application/     # Commands, Queries, MediatR pipeline
│   │   ├── Infrastructure/  # EF Core, Outbox, RabbitMQ
│   │   └── API/             # Controllers, Middleware, Program.cs
│   ├── NotificationService/ # MassTransit consumers + Hangfire
│   └── ApiGateway/          # YARP + JWT validation
├── tests/
│   └── OrderService.Tests/  # Unit + Integration tests (Testcontainers)
├── benchmarks/
│   └── OrderService.Benchmarks/  # BenchmarkDotNet — Dapper vs EF Core
├── infra/
│   ├── docker/              # Dockerfiles
│   ├── helm/                # Kubernetes Helm charts
│   └── otel/                # OpenTelemetry collector config
└── docker-compose.yml

---

Test Credentials

User	Password	Role
trader1	Password123!	Trader
trader2	Password123!	Trader
svc-internal	InternalPass!	InternalService