@startuml
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml

LAYOUT_LEFT_RIGHT()

title LOTTY - C4 Container

Person(product_client, "Product Client", "Web/Mobile app")
Person(ops_user, "Experimenter/Approver/Admin/Viewer")

System_Boundary(lotty_boundary, "LOTTY Backend") {
  Container(api, "Backend API", "Django + Ninja", "REST endpoints: flags, experiments, decide, events, reports, guardrails, notifications, conflicts, metrics, learnings, reviews, users, auth")
  ContainerDb(db, "PostgreSQL / SQLite", "Relational DB", "Experiments, variants, decisions, events, exposures, outcomes, guardrails, notifications, conflicts, logs")
  Container(cache, "Valkey / Redis / LocMem Cache", "Cache + Celery broker", "Flag/experiment/decide-result cache, Celery task broker")
  Container(worker, "Celery Worker / Beat", "Background worker", "Periodic jobs + async decision persistence")
}

System_Ext(notifications, "Notification Channels", "Telegram / SMTP")

Rel(product_client, api, "Gets flag decisions, sends events", "HTTP/JSON")
Rel(ops_user, api, "Admin/experiment/review calls", "HTTP/JSON")
Rel(api, db, "Read/write application state", "SQL")
Rel(api, cache, "Read/write cache, enqueue async tasks", "Redis protocol")
Rel(worker, db, "Read/write application state", "SQL")
Rel(worker, cache, "Consumes tasks, reads cached state", "Redis protocol")
Rel(worker, notifications, "Delivers queued notifications", "HTTP / SMTP")

@enduml