With EventSourcing ever-growing popularity, many voices start to express worries about the underlying technical complexity of the pattern. It appears that not only the pattern needs serious considerations before applying, but also requires extensive technical knowledge of its implementation.
These days, it is quite easy to find materials online about motivations for using EventSourcing. But when it comes to practical aspects of the implementation, we can't say the same.
Such a situation often leads to confusion when developers make repeated mistakes and conclude the pattern itself as a failure.
I build event-sourced systems for a living and have a substantial record of successful implementations during the last several years. Some systems I helped implementing are smaller, some are larger, but they share the same characteristics - stability, performance and high level of observability to help to maintain these systems.
In this talk, I'd like to share my experience with you and explain some of the common pitfalls on the way to a production-grade application that uses EventSourcing in its core. I will also provide a set of heuristics that help me make decisions about particular implementation style for different kinds of event-driven service or application.