Talk: 10:15-11:00 (English)

Event Sourcing without Responsibility

This is a follow-up to Andreas Bernauer’s talk from BOB 2016: The talk examines the implementation of event-sourcing in a highly distributed application for configuration management in a large network of car shops among mobile devices that are only sporadically connected.

When building an event-sourced systems, it’s a common reflex to construct projections to answer queries instead of sifting through the event stream, using the CQRS paradigm. However, CQRS might not quite be the best way to organize an event-sourced system: The concept of “responbility” is foggy in many contexts, and the separation between “read models” and “write models” is the wrong axis to use for organizing storage and indexing. Moreover, CQRS may lead to implementing read models prematurely and unnecessarily.

We demonstrate how the implementation of event sourcing and CQRS played out in our configuration-management application, and reflect the implications for the architecture of future systems.

Michael Sperber


Michael Sperber is CEO of Active Group in Tübingen, Germany. Mike specializes in software architecture using functional programming.