State or Events? Which Shall I Keep?
Tired of fancy abstractions without actual down to earth implementation? In this talk we will go through both benefits and problems by implementing a real example of event-sourced model. This is a full-time live coding and we will develop features in parallel - one of us in a classic ORM-based way and the other one using event sourcing. We are going to tackle the problems step by step in both solutions from various perspectives. From the point of view of the stakeholders our software should have quick time to market, ability to do complex data reporting and fast way to extend and to deploy new features. On the other hand, our fellow developers would be interested in learning curve when it comes to event sourcing and how it differs in turns of e.g. unit testing. At the end of each step it will be clear what kind of problems/benefits we have using one of two models. The talk is going to cover a broad set of buzzwords like: event sourcing, CQRS, distributed systems, spring cloud stream, eventual consistency, unit testing and zero downtime deployments.