@startuml
title MVP Notification System (Polling)

left to right direction

actor User
rectangle "Backend (Python)" {
  component "App Logic" as App
  database "notifications table" as DB
  component "GET /api/notifications/unread" as API
}

rectangle "Frontend (React)" {
  component "Poller (30s)" as Poller
  component "Browser Notification API" as BrowserAPI
}

App -> DB: INSERT notification
Poller -> API: Poll every 30s
API -> DB: SELECT WHERE user_id AND read=false
API --> Poller: JSON array
Poller -> BrowserAPI: Show popup
BrowserAPI -> User: Desktop notification

note right of DB
  Simple schema:
  - id
  - user_id
  - event_type
  - message
  - created_at
  - read (boolean)
end note

note bottom of Poller
  No WebSockets needed
  1000 users × 2 req/min
  = ~33 req/s (trivial load)
end note
@enduml