This month an article I wrote for PHP Architect, called “CQRS & Event Sourcing in the Wild”, was published in the December 2017 “Talking Code” issue.
Requirements and applications evolve and change, leading to refactoring. For example, user registration now requires a first and last name, what was once an error may no longer be considered one, etc. In an event sourced application, that poses a few problems. In this post I’ll discuss a few strategies and my views on event versioning.