Comprehensive Guide to Implementing ES/CQRS with EventStoreDB, Phoenix, and LiveView

Yevhenii Kurtov discusses the implementation of an Event Sourcing (ES) and Command Query Responsibility Segregation (CQRS) system using Phoenix/LiveView and EventStoreDB. The article provides a detailed walkthrough of creating a loan processing system where users can apply for loans, and various steps are followed based on their credit score. The tutorial covers setting up EventStoreDB, connecting it to Elixir using the Spear client, and managing commands and events flowing through the system. It also delves into generating a read model for an underwriter's dashboard, handling real-time updates with Pub/Sub, and ensuring message processing guarantees. The post explains state management using event sourcing, ensuring eventual consistency, and evolving the system in a functional programming paradigm. It integrates contextual guidance for scaling and practical considerations for production scenarios, aiming to help developers build robust, scalable, and maintainable ES/CQRS systems.