Titles can be misleading. No special guest this time, but I’d like to introduce you to Emmett. Oh well, most importantly, I'd like to introduce you to Event Sourcing and show you how straightforward it can be. I believe that TypeScript, Node.js, and Emmett can help with that.

For many years, I’ve tried convincing others that Event Sourcing is not so scary and quite useful. I truly believe in that, yet…

I see a chasm between its initial simplicity and its use in production. In our past webinar, Alexey Zimarev said we need Event Sourcing frameworks. After thinking about it, I agree with that take. We’re not yet in the adoption phase to not need a framework or library.

Over a year ago I started packing my Node.js samples into the package, which resulted in…

Emmett: a framework that will take your applications back to the future.

The idea behind Emmett was to make it easier to create business-focused applications and cut unnecessary code without using magic. The combination of using events and their business focus, the expressiveness of TypeScript and the lightness of Node.js is supposed to help with that.

During the webinar I showed step by step:

• What’s Event Sourcing,

• How to model and tell the story about your business process using events,

• How to reflect that in the code, so modelling events, command, business logic,

• How to test Event Sourcing business logic with Behaviour-Driven Design,

• Joining that into REST WebApi,

• using PostgreSQL based storage,

• build read models.

All of that is in a 1.5-hour webinar. So fasten your seat belts, watch the recording and tell me what you think.

See the full source code for what we did during the webinar: https://github.com/event-driven-io/emmett-starter-postgresql.

This is open content with no paid wall, so I’d appreciate resharing it with your friends!

If you want to learn more about Event Sourcing and ramp up your journey, I’ll be doing an open workshop with Avanscoperta on April 3rd—4th, 7th—8th, 2025. You can sign up too! Sign up here: https://www.avanscoperta.it/en/training/practical-introduction-to-event-sourcing-workshop/

We’ll do learning in a similar hands-on spirit!

Check more about Emmett in:

• Emmett documentation

• Emmett Discord Channel

• Announcing Emmett! Take your event-driven applications back to the future!

• Event Sourcing on PostgreSQL in Node.js just became possible with Emmett

• Writing and testing event-driven projections with Emmett, Pongo and PostgreSQL

• Idempotent Command Handling

• Event Sourcing with Emmett: Reducing the Entry Barrier by Mário Bittencourt

• Testing Event Sourcing, Emmett edition

• Using event metadata in event-driven projections

• How to configure a custom Test Container on the EventStoreDB example

Cheers!

Oskar

Other Webinars

• #1 - From CRUD to Event Sourcing

• #2 - Keep your streams short! Or how to model Event-Sourced systems efficiently

• #3 - Implementing Distributed Processes

• #4 - From CRUD to CQRS in Practice

• #5 - Architecture Weekly 100 Edition - Live Q&A

• #6 - Alexey Zimarev - You don't need an Event Sourcing framework. Or do you?

• #7 - Design and test Event-Driven projections and read models

• #8 - Slim down your aggregates!

• #9 - Radek Maziarka - Modularization with Event Storming Process Level

• #10 - PostgreSQL Superpowers in Practice

• #11 - Maciej "MJ" Jędrzejewski - Evolutionary Architecture: The What. The Why. The How.

• #12 - Jeremy D. Miller: Simplify your architecture with Wolverine

• #13 - Yves Goeleven - The Fantastic 9

• #14 - Mateusz Jendza - Why Verified Credentials is the Future of Digital Identity!

• #15 - Mário Bittencourt: Leveraging BPMN for Seamless Team Collaboration in Software Development

• #16 - Papers We Love #1 - Sagas (Hector Garcia-Molina, Kenneth Salem)

• #17 - Simple patterns for events schema versioning

• #18 - Andrea Magnorsky: Introducing Bytesize Architecture Sessions!

• #19 - Laïla Bougriâ: Debug your thinking

• #20 - Papers We Love #2 - How do committees invent? (Melvin E. Conway)

• #21 - Michael Drogalis: Building the product on your own terms

• #22 - On Performance Testing with Jarosław Pałka

• #23 - Gojko Adzic on designing product development experiments with Lizard Optimization

• #24 - Frontent Architecture, Backend Architecture or just Architecture? With Tomasz Ducin

• #25 - Applying Observability: From Strategy to Practice with Hazel Weakly

• #26 - React Query: A solution for Frontend State Management challenges? With Tomasz Ducin

• #27 - Documenting Event-Driven Architecture with EventCatalog and David Boyne

• #28 - Practical Introduction to Event Sourcing with Emmett