flowchart LR
  subgraph Clients
    Web[Web App (Browser)]
    Mobile[Mobile Apps]
  end

  subgraph Edge
    WAF[WAF / CDN]
    APIGW[API Gateway]
  end

  subgraph CoreServices[Core Backend Services]
    Auth[Auth & Identity\n(OAuth2 / JWT)]
    Tenant[Tenants & Companies]
    Estates[Estates & Projects]
    Inventory[Properties & Inventory]
    CRM[Clients & CRM]
    Sales[Sales & Reservations]
    Allocation[Allocations]
    Payments[Payments & Installments]
    Agents[Agents & Commissions]
    Docs[Documents & Files]
    Reports[Reporting & Analytics]
    Notify[Notifications]
    Audit[Audit & Activity Logs]
  end

  subgraph DataPlane[Data & Infra]
    DB[(Relational DB\n(PostgreSQL/MySQL))]
    Search[(Search Index\n(Elasticsearch/OpenSearch))]
    Cache[(Redis Cache)]
    Bus[(Event Bus\n(Kafka/RabbitMQ))]
    Storage[(Object Storage\n(S3-compatible))]
    Metrics[(Metrics & Traces)]
    Logs[(Centralized Logs)]
  end

  Web --> WAF --> APIGW
  Mobile --> WAF
  WAF --> APIGW

  APIGW --> Auth
  APIGW --> Tenant
  APIGW --> Estates
  APIGW --> Inventory
  APIGW --> CRM
  APIGW --> Sales
  APIGW --> Allocation
  APIGW --> Payments
  APIGW --> Agents
  APIGW --> Docs
  APIGW --> Reports
  APIGW --> Notify
  APIGW --> Audit

  Auth --> DB
  Tenant --> DB
  Estates --> DB
  Inventory --> DB
  CRM --> DB
  Sales --> DB
  Allocation --> DB
  Payments --> DB
  Agents --> DB
  Docs --> DB
  Reports --> DB
  Notify --> DB
  Audit --> DB

  Inventory --> Search
  CRM --> Search

  Sales --> Bus
  Allocation --> Bus
  Payments --> Bus
  Notify --> Bus
  Agents --> Bus

  Docs --> Storage

  CoreServices --> Cache

  CoreServices --> Metrics
  CoreServices --> Logs