Как улучшить Enterprise архитектуру при помощи CQRS

CQRS (Command Query Responsibility Segregation): A Deep Dive into System Architecture

Discover the power of CQRS (Command Query Responsibility Segregation), a robust architectural pattern that separates your system into distinct command and query sides. This approach optimizes performance and scalability by allowing you to tailor data handling for different operations.

What is CQRS?

CQRS fundamentally divides your system into two independent components:

• Command Side: Responsible for changing data. Typically interacts with a normalized relational database using Object-Relational Mapping (ORM).
• Query Side: Dedicated to reading data without modification. Often utilizes a denormalized data store optimized for fast data retrieval.

This separation significantly boosts read performance, especially crucial for backend systems where queries often outweigh write operations.

Why Learn CQRS?

While CQRS isn't a new concept, its adoption lags behind technologies like microservices and DDD. Many developers hesitate due to perceived complexity. This course will demonstrate the substantial benefits of vertical CQRS handlers over traditional horizontal services, revealing eight key advantages for system architecture. We'll also address and dispel common concerns surrounding CQRS implementation.

Course Content: What You'll Learn

This comprehensive course begins with clarifying key terminology: CQS, CQRS, Vertical Slices, and Feature by Folder. We'll then explore the practical application of CQRS using a real-world "e-commerce" demo application. Through a hands-on example, you'll see the differences between horizontal layered architectures and vertical CQRS implementations. The project will evolve as we add and modify features, showcasing:

• Returning Values from Commands: Learn how to effectively return data from command handlers.
• ApplicationService vs. CQRS Handlers: Understand the role of each component in your application.
• DTOs for Commands and Queries: Explore whether to use Data Transfer Objects (DTOs) for command and query data.
• Mass Registration of CQRS Handlers: Discover how to efficiently register handlers within a Dependency Injection (DI) container.
• Code Reusability: Learn techniques to share code between different use cases.
• The Future of Application Services: Determine if Application Services are still necessary when using CQRS handlers.
• Migrating from Layers to Handlers: A practical guide to migrating your application architecture, including refactoring techniques.
• CRUD Implementation: Compare and contrast CRUD (Create, Read, Update, Delete) scenarios for services and handlers, identifying the optimal approach.
• Use Case Invocation: Understand how to invoke use cases, both implicitly (for services) and explicitly (for handlers).
• Cross-Cutting Concerns: Learn how to implement cross-cutting concerns effectively in both services and handlers.
• Unit Testing: Explore differences in unit testing strategies for services and handlers.
• Result Handling: Evaluate the benefits of using Result types for improved architecture and performance.
• CQRS Engine Analysis: We'll analyze existing CQRS engines, select the best fit, and discuss the pros and cons of using a pre-built engine versus building your own.

Who is this course for?

This course is designed for backend developers building business applications. It's for those who strive to create systems that are easy to maintain, evolve, and improve.

The demo project is built using C# and ASP.NET Core, but the concepts are language and platform agnostic. The principles taught here are applicable to backend development in Java, Python, JavaScript, Ruby, Go, PHP, and more. Gain the skills to build scalable, high-performance systems that you can be truly proud of!