Lab

Event-driven laboratory

To finish: free experiments over the whole architecture. Pick a scenario, turn on any defences, change how services and the network behave, and watch the flow in parallel by service and step by step.

Scenario

Event-driven defences

More mechanisms (Event Sourcing, CQRS, Saga)

Services in the architecture

Network and broker

Services and their behaviour

Service	Online	Latency (ms)	Failure rate (%)	Duplicates (%)	Out of order	Lost ack	Inbox	Max retries

Speed

Architecture and event flow

In parallel: services over time

Window

Event Store: append-only history D domain · I integration · C command · click an event for details

Message Broker (simulated): delivery ➤ published · 📤 outbox · ✓ processed · ✗ failed · ↻ retry · ☠ DLQ · ⧉ duplicate · ⊘ ignored · ⏸ buffer · ✂ lost

Event detail

Sequentially: step by step

Step by step (newest on top)

Event Store: append-only history (newest on top)

Message Broker: delivery (newest on top)

Projection (current state)

The laboratory needs JavaScript. Without it, go through the exercises: each has a recording of the experiment. All exercises

Training for your team

Would you like this training for your team?

We run the training on your code and your domain problem. We agree the scope, dates and format with you.

Discuss the training