Effective Aggregate Modelling (with the Aggregate Design Canvas)

Friday afternoon 14:00 - 16:00 CET (UTC+1)


Kacper Gunia


Designing an aggregate with the right boundaries and clear responsibilities is not a trivial task. A lot of times people rely on gut feeling or implicit heuristics to guide modelling decisions. Depending on these decisions and chosen consistency boundaries, we might be able to enforce business invariants or will have to put some corrective policies in place. Because of that, it is important to evaluate multiple designs of the aggregates, as they impact behaviours modelled within our domain.

During the workshop, you will have an opportunity to model and document an aggregate in practice using the Aggregate Design Canvas. It is a tool created to guide your modelling process, make the design decisions explicit, reason about concurrency conflicts and the size of data persisted in the underlying storage. The goal of the lab is to model an aggregates used in healthcare booking system, and we need your help to decide whether it should be a single slot, a whole year worth of slots or something in between!

About Kacper Gunia

Trainer, Consultant & DDD London Organiser Twitter LinkedIn Blog Company Website

Kacper Gunia is an independent Software Architect, Trainer and Consultant with 10 years of experience in the industry. He is passionate about delivering value by creating software that is aligned with the business as well as by enabling teams to be successful & productive with Domain-Driven Design and other methodologies. Kacper worked with clients including Starbucks, Time Inc, GFT, Sportradar & Government agencies. In his spare time he runs Domain-Driven Design London meetup.