I started working on Eventuous, a set of libraries for .NET that help people to start building event-sourced systems, in January 2021. Fifteen months ago, on 25 March 2021, the first version (0.1.0) found its way to NuGet. What happened between then and now? As I write this post, Eventuous…

Eventuous is an OpenSource Event Sourcing library for .NET. Read mode at https://eventuous.dev All the versions of Eventuous before 0.10 had the aggregate identity as part of the aggregate state by default, you weren’t able to avoid having it there. As a developer, you were also required to set the…

In event-sourced systems, the domain model is using events as the source of truth. These events represent individual and atomic state transitions of the system. We add events to the event store one by one, in an append-only fashion. When restoring the state of an aggregate, we read all the…

What is Eventuous Connector and how to use it Eventuous connectors allow subscribing to events from EventStoreDB (source) and produce derived events to another system (sink). Some sinks also support reduce-like operations that work as projections. The Connector is a combination of a real-time subscription (currently only to $all stream)…

Real-time subscriptions are essential when building a successful event-sourced system. They support the following sequence of operations: The domain model emits a new event The event is stored in the event store The command is now handled, and the transaction is complete All the read models get the new event…

As a listened to more of the Ask me anything with Udi Dahan session organised by Virtual DDD, more points, which Udi was making, especially about Event Sourcing, made my fingers itch to write some more. When talking about the natural progression in system evolution once it’s in production, Udi…

Event Sourcing done right, as it is meant to be. Don’t get caught up in the misconception that Event Sourcing is the same thing as Event-Driven Architecture. If you ever searched for a diagram that can give you an idea of what Event Sourcing is about, you can find many…

Ok, I can finally formulate what I meant. Looking at the dictionary: "Domain - a specified sphere of activity or knowledge." Uber domain is ride sharing. Indeed, it has multiple subdomains, which deal with finances for drivers, finances for passengers, reviews, all that. I can't imagine a discussion "how big…