ModelingEvolution.Booking

Meeting booking as an event-sourced module on MicroPlumberd 1.2.x / KurrentDB: one BookingCalendar-{mailbox} stream arbitrates non-overlap of meetings on a mailbox (optimistic concurrency — a lost version race retries once, then refuses as slot_taken); each booking lives on its own Booking-{BookingId} stream (MeetingBooked, MeetingCancelled); availability is synced from O365 and offered per meeting type; bookings carry an ExternalReference (kind:value) a consumer uses to find them again.

builder.Services.AddPlumberd(KurrentDBClientSettings.Create(connectionString));
builder.Services.AddBooking(builder.Configuration);   // command handlers, read models, calendar integration (Booking:* options)

Read models: BookingLookupModel (by id / by reference), AvailableSlotsModel, BookingConfigModel. The concurrency invariant is tested against a real KurrentDB in the source repository (RealStoreSlotArbitrationTests), on both the pre- and post-1.2 client libraries.