Four .NET 10 services — Identity, Flight, Passenger, Booking — each owning its data, talking over gRPC when a call must be synchronous and over RabbitMQ when it need not be. An API gateway in front, OpenTelemetry underneath. One command brings the whole thing up locally.
You need the .NET 10 SDK and Docker Desktop. Everything else runs in containers.
So the containers can serve TLS: dotnet dev-certs https -ep ~/.aspnet/https/aspnetapp.pfx -p password, then dotnet dev-certs https --trust.
aspire run starts every service and its infrastructure. The dashboard with logs, traces and metrics is at localhost:18888.
Every service serves OpenAPI at /swagger and /scalar/v1. Open booking.rest in VS Code's REST Client to authenticate as van1 and walk through a booking.
Prefer Docker Compose or Kubernetes? Both live in deployments/:
docker-compose -f ./deployments/docker-compose/docker-compose.infrastructure.yaml up -d # infrastructure only docker-compose -f ./deployments/docker-compose/docker-compose.yaml up -d # full stack kubectl apply -f ./deployments/kubernetes/booking-cert-manager.yml kubectl apply -f ./deployments/kubernetes/booking-microservices.yml
Each service is small on the outside and organised by feature on the inside.
Code is grouped by feature, not by layer. Flights/Features/CreatingFlight/V1/ holds the endpoint, the command, its handler, the validator and the events it raises. A change to one use case touches one folder. MediatR runs a pipeline with validation and logging behaviours around every request.
Commands change the write store: PostgreSQL for Flight, Passenger and Identity, EventStoreDB for Booking, which is fully event-sourced. Consumers project the resulting events into MongoDB read models. Queries only ever read MongoDB.
Integration events leave through Wolverine's durable outbox to RabbitMQ (at-least-once delivery) and arrive through a durable inbox (idempotent, exactly-once processing). When Booking must confirm a flight or a passenger right now, it calls that service over gRPC instead.
YARP is the public entry point and routes to the services. Duende IdentityServer issues OpenID Connect / OAuth2 tokens; the seeded users van1 (admin) and van2 (user) are enough to try every endpoint.
Unit tests with NSubstitute, integration and end-to-end tests that start PostgreSQL, MongoDB and RabbitMQ through Testcontainers, and consumer-driven contract tests with PactNet. dotnet test runs them all; Docker must be running.
Every service owns its data and exposes a small REST surface through minimal APIs.
| Service | Responsibility | Write store | Read store |
|---|---|---|---|
| Identity | Users, roles, tokens (IdentityServer) | PostgreSQL | — |
| Flight | Flights, airports, aircraft, seats | PostgreSQL | MongoDB |
| Passenger | Passenger profiles | PostgreSQL | MongoDB |
| Booking | Booking a seat on a flight for a passenger | EventStoreDB | MongoDB |
| ApiGateway | Single public entry point (YARP) | — | — |
| Aspire AppHost | Local orchestration and dashboard | — | — |
Traces, metrics and logs leave every service through OpenTelemetry to a collector, then on to Jaeger, Prometheus, Grafana and Serilog with Kibana. Polly handles retries and circuit breaking; ASP.NET Core health checks report readiness. CSharpier, Husky and commitlint enforce formatting and Conventional Commits before each commit.