Payment Services

Built a reactive payment processing backend using Java, Spring Boot, WebFlux, MongoDB, and Kafka, implementing event-driven payment workflows, REST APIs, CI/CD automation, testing, and microservices-ready architecture for real-time transaction processing.

Features

• Create a payment
• Retrieve a payment by ID
• Retrieve all payments or filter by customer ID
• Update payment status
• Publish Kafka events whenever a payment is created or updated
• Reactive, non-blocking REST APIs using WebFlux
• CI pipeline for build + test validation

API Endpoints

Create Payment

POST /api/v1/payments

Sample request:

{
  "orderId": "ORD-1001",
  "customerId": "CUST-901",
  "amount": 249.99,
  "currency": "USD",
  "paymentMethod": "CARD"
}

Get Payment by ID

GET /api/v1/payments/{paymentId}

Get All Payments

GET /api/v1/payments

Get Payments by Customer

GET /api/v1/payments?customerId=CUST-901

Update Payment Status

PATCH /api/v1/payments/{paymentId}/status

Sample request:

{
  "status": "CAPTURED"
}

Running Locally

1. Start MongoDB and Kafka

docker compose up -d

2. Run the application

mvn spring-boot:run

Application runs at:

• API: http://localhost:8080
• Swagger UI: http://localhost:8080/swagger-ui.html

Build and Test

mvn clean test package