Restaurant Subdomain

The Restaurant subdomain handles the core operations that occur within each Reactive BBQ location. This is where customers interact with the restaurant through the front-of-house staff and where food is prepared in the kitchen.

Bounded Contexts

Based on the personnel interviews, we identify several bounded contexts within the Restaurant subdomain:

Front of House

Handles customer-facing operations:

• Reservations - Taking and managing table reservations
• Seating - Tracking table availability and seating guests
• Ordering - Taking food and drink orders at tables
• Payment - Processing bills and collecting payments

Key entities: - Table - Physical table with capacity and status - Reservation - Booking with time, party size, preferences - Order - Collection of items for a table - Bill - Itemized charges for an order

Kitchen

Handles food preparation:

• Order Queue - Tracking orders to be prepared
• Station Management - Assigning cooks to stations
• Quality Control - Chef approval before serving

Key entities: - Ticket - Kitchen's view of an order to prepare - Station - Prep station (grill, fryer, salad, etc.) - MenuItem - Recipe and preparation instructions

Bar

Handles drink service:

• Drink Orders - Preparing drinks for tables and bar customers
• Bar Tabs - Tracking charges for bar customers
• Inventory - Managing bar stock

Communication Patterns

The Restaurant subdomain uses event-driven communication:

context FrontOfHouse is {
  entity Order is {
    handler OrderHandler is {
      on command PlaceOrder {
        // Emit event for kitchen
        send event OrderPlaced to Kitchen.OrderQueue
      }
    }
  }
}

When a server places an order, an OrderPlaced event is sent to the Kitchen context, which adds it to the preparation queue. This decoupling means the front-of-house doesn't block waiting for the kitchen.

Challenges Addressed

This design addresses issues from the interviews:

Challenge	Solution
Slow order entry	Async event-driven, no blocking
Terminal contention	Servers can use mobile devices
System failures	Event sourcing enables recovery
Kitchen order loss	Persistent event log

Source Code

See the Restaurant subdomain implementation: restaurant/domain.riddl