Services and Responsibilities

Services Table

Service	Owns (data)	Main APIs	Publishes	Consumes
product-service	Product, Category	`GET /api/products`, `GET /api/products/{id}`, admin CRUD	ProductUpdated	—
user-service	User, Address	`GET /api/users/me`, addresses	UserRegistered	—
cart-service	CartItem (Redis)	`GET/POST/DELETE /api/cart`	—	ProductUpdated (price changes)
order-service	Order, OrderItem, saga_instance, outbox	`POST /api/orders`, `GET /api/orders/{id}`	OrderCreated, OrderConfirmed, OrderCancelled, commands	StockReserved/Rejected, PaymentCompleted/Declined
inventory-service	Stock, Reservation	internal only	StockReserved, StockRejected, StockReleased	ReserveStock, ReleaseStock
payment-service	Payment, Refund, idempotency_record	`POST /api/payments/webhook` (Razorpay)	PaymentCompleted, PaymentDeclined, Refunded	ChargePayment, RefundPayment
notification-service	Notification log	internal only	—	OrderConfirmed, OrderCancelled, Refunded

Note: Product.stock from the shared ShopEase model now lives in inventory-service as the source of truth; product-service only shows an "in stock" flag updated from inventory events.

Kafka Topics

Topic	Key	Producer	Consumers	Partitions
`order-events`	orderId	order-service (outbox)	notification, analytics, order-query	12
`inventory-commands`	orderId	order-service (saga)	inventory-service	12
`inventory-events`	orderId	inventory-service (outbox)	order-service (saga)	12
`payment-commands`	orderId	order-service (saga)	payment-service	12
`payment-events`	orderId	payment-service (outbox)	order-service, notification	12
`*.DLT`	same	error handlers	on-call engineers / replay tool	1

Repository Layout

shopease/                          (monorepo)
├── api-gateway/
├── web-bff/   mobile-bff/
├── product-service/   user-service/   cart-service/
├── order-service/
│   ├── src/main/java/com/shopease/order/
│   │   ├── api/           OrderController, DTOs
│   │   ├── domain/        Order, OrderItem, OrderStatus
│   │   ├── saga/          OrderSagaOrchestrator, OrderSaga, replies
│   │   ├── outbox/        OutboxEvent, OutboxRelay
│   │   └── client/        ProductClient (RestClient + Resilience4j)
│   ├── src/main/resources/db/migration/   V1__orders.sql, V2__outbox.sql
│   └── Dockerfile
├── inventory-service/   payment-service/   notification-service/
├── k8s/                     Kustomize base + overlays (staging, prod)
├── docker-compose.yml       local development
└── .github/workflows/       one workflow per service