Blog
Mert Özen's blog posts on software development, backend, frontend, and DevOps.
The Evolution of DDD and Common Mistakes: From the Blue Book to Dynamic Consistency Boundaries
DDD's most common mistake is skipping the strategic design left at the end of the Blue Book and taking only tactical words like entity, repository, and base class. A history from Evans's 2003 book to the DDD Reference, Vernon's aggregate rules, EventStorming, Team Topologies and Khononov, and the Dynamic Consistency Boundary that questions the aggregate; with an in-memory DCB example and a reading route after the series.
Aggregate Design: Consistency Boundaries, Small Aggregates, and Referencing by Id
An aggregate is a consistency boundary that keeps true invariants consistent within a single transaction; the outside references only the root, and other aggregates are referenced only by id. We apply Vernon's four rules to Bookstore's Order and StockItem aggregates and work through a real EF Core run where a navigation property silently changes the catalog price, eventual consistency for stock, the 'whose job is it?' question and the Aggregate Design Canvas.