021: From Active Record Business Logic to DDD & Events with Andrzej Krzywda

The Rails Changelog

Andrzej Krzywda discusses event sourcing, event-driven architecture, and Domain-Driven Design (DDD) in the context of Ruby on Rails applications. He explains the concept of bounded contexts and how they relate to communication between different modules. He also shares insights on when and why to apply DDD to Rails applications, particularly in cases where the application becomes complex and difficult to maintain. Andrzej explores the challenges and benefits of migrating an existing Rails app to an event-driven architecture and highlights advanced event sourcing concepts such as snapshotting, projections, and versioning. In this conversation, Andrzej Krzywda discusses event sourcing and DDD in Rails applications. He explains the concepts of snapshotting and projection, which are techniques used to optimize performance and retrieve specific data from event streams. Andrzej also delves into the challenges of event versioning and how it can be managed in Rails applications. Additionally, he shares insights about the wroclove.rb conference, its history, and its focus on advanced and deep technical topics.

Takeaways
Event sourcing is a persistence mechanism that persists all the little changes that happen to a specific object, while event-driven architecture is a way of building software modules that communicate with events.

DDD involves splitting a system into contexts or domains and using events to communicate between them. It can be applied to Ruby on Rails applications, particularly in cases where the application becomes complex and difficult to maintain.
Migrating an existing Rails app to an event-driven architecture can help address issues with large classes, complex associations, and lack of modularity.

Advanced event sourcing concepts such as snapshotting, projections, and versioning can be used to optimize performance and manage data integrity in event-driven applications. Snapshotting and projection are techniques used in event sourcing to optimize performance and retrieve specific data from event streams.

Event versioning is a challenge in event sourcing, but it can be managed by introducing new event versions and implementing upcasters to convert old events to new versions.

wroclove.rb is a Ruby and Rails conference in Wrocław, Poland, that focuses on advanced and deep technical topics.
The conference aims to inspire, educate, and challenge the status quo in the Ruby and Rails community.
Rails Event Store and Eventide are two libraries that facilitate the implementation of event-driven architectures in Rails applications, each with its own philosophy and approach.

wcrolove.rb Ruby and Rails Conference
RailsEventStore
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Rails Architect Masterclass
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