Critter Stack Workshops

Training material for CQRS and Event Sourcing with the Critter Stack — Marten, Polecat, and Wolverine.

Eight hours of material, delivered as four two-hour blocks. See OUTLINE.md for the full breakdown.

Layout

OUTLINE.md	Master outline — sections, timing, and what maps from the old decks
slides/	Eight Slidev decks, one per section
src/	Sample applications the decks import their code from
Old/	The previous workshop — original samples and .pptx decks, archived

Getting set up

You need the .NET 10 SDK and Docker Desktop.

docker compose up -d

Postgres lands on 5440 and Rabbit on 5682, not the default ports. That keeps the workshop from colliding with anything else you already have running — including a local Postgres on 5432, which many people have. If you go looking for the workshop database on the default port, that is why it isn't there.

Verify the environment:

cd src/01-quickstarts/DocumentQuickstart && dotnet run

That's everything you need to follow along. Node is only required if you also want to run the slide decks yourself — see below.

Sample code

src/01-quickstarts/	Two console apps for section 1 — documents, then event sourcing
src/HelpDesk/	The modular monolith that sections 2–8 demonstrate against — see its README

dotnet test src/HelpDesk/HelpDesk.Tests

Running the slides

The decks are Slidev. Optional — you don't need them to work through the samples — but they're the fastest way to review the material, and the code on the slides is imported live from src/, so it can't drift.

Needs Node 20+. Once:

npm install

Then open a section, s1 through s8:

npm run s1 --workspace slides

That serves the deck at http://localhost:3030 and hot-reloads as you edit — both the markdown and the C# it imports. Useful keys while presenting:

o	overview grid of every slide
f	full screen
d	toggle dark mode
p	presenter view, with a second window for the audience

Build all eight decks to static sites, or export them to PDF as a fallback for a projector that won't cooperate:

npm run build --workspace slides
npm run export --workspace slides

Code in the slides

Slides never contain copy-pasted code. Every sample is imported by name out of a real, compiling project in src/, the same way the Marten and Wolverine docs do it.

In the C#:

#region sample_es_time_travel
var asOfVersion1 = await session.Events.AggregateStreamAsync<Incident>(incidentId, version: 1);
#endregion

In the deck:

<<< ../src/01-quickstarts/EventSourcingQuickstart/Program.cs#sample_es_time_travel cs

Regions follow Marten's sample_* naming convention. Slidev resolves them at build time, so a slide can never drift from the code it claims to show.

npm run build runs verify-snippets.mjs first, which fails the build if any deck references a file or region that no longer exists. Run it on its own with:

npm run verify --workspace slides

The workspaces field in the root package.json is load-bearing — Slidev sandboxes snippet imports to the workspace root, and the decks import from ../src.