A practical walkthrough of implementing Vertical Slice Architecture in a hotel room reservation module using C#, CQRS, and Event Sourcing with Marten. The post demonstrates how to organize code by business feature using feature folders, showing concrete examples of commands, event handlers, read models, and projections. It covers handling multiple input sources (API and external systems like Booking.com), overbooking detection via Marten change listeners, and managing cross-module dependencies with explicit boundaries. The final folder structure groups all related logic — commands, endpoints, projections, and queries — under a single business operation folder.
2 Impressions