Databases

Command Query Responsibility Segregation (CQRS) is an architectural pattern that separates read and write operations in your application. While it adds complexity, CQRS can provide significant benefits for applications with complex business logic, different read/write workloads, or high scalability requirements. Let’s explore how to implement it effectively. Why Consider CQRS? Before diving into implementation, let’s understand when CQRS makes sense: Different Scaling Needs: Your read and write workloads have different scaling requirements Complex Business Logic: Your write operations involve complex business rules Performance Optimization: You need to optimize read and write operations independently Eventual Consistency: Your system can tolerate eventual consistency for read operations Core Components of CQRS Command Stack Implementation The command stack handles all write operations. Here’s how to implement it in TypeScript: ...

In modern distributed systems, maintaining data consistency, tracking changes, and scaling effectively can be challenging. Event Sourcing offers a powerful architectural pattern that addresses these challenges by storing all changes to an application’s state as a sequence of events. Let’s explore how to implement this pattern in a production environment. Why Event Sourcing? Before diving into implementation details, let’s understand why you might want to use Event Sourcing: Complete Audit Trail: Every state change is captured as an immutable event, providing a perfect audit history. Temporal Queries: You can determine the system’s state at any point in time by replaying events. Debug Friendly: When issues occur, you have a complete history of what led to the current state. Event Replay: You can fix bugs by correcting the event handling logic and replaying events. Scale Write/Read Separately: Event storage and read models can be scaled independently. Core Components The Event Store The Event Store is the heart of any event-sourced system. It’s responsible for storing and retrieving events while ensuring consistency. Here’s a TypeScript implementation that handles the core functionality: ...