PlantUML — Component

@startuml
package "Frontend" {
  [Web SPA]
  [Mobile App]
}
package "Backend" {
  [API Gateway] as API
  [Auth Service]   as Auth
  [Order Service]  as Order
  [Payment Service] as Pay
}
database "Postgres" as PG
queue    "Kafka"    as MQ

[Web SPA]   --> API
[Mobile App]--> API
API --> Auth
API --> Order
Order --> Pay
Order --> MQ
Auth --> PG
Order --> PG
@enduml