Vertical Slice Architecture: An Agile Companion to Clean Architecture

In the last article we discussed Clean Architecture Using ASP.NET using packages and how to segregate the code base to be ‘Clean’. Today, we shift our focus to a compelling counterpart – Vertical Slice Architecture (VSA). Strap in as we slice through the traditional layers of coding to unveil a more feature-focused methodology.

Introduction

Imagine slicing through the layers of your application, from the user interface to data storage, each slice encapsulating a full stack of functionality. This is the essence of Vertical Slice Architecture, a method that eschews traditional technical segmentation in favor of organizing code around features or business capabilities. While Clean Architecture serves as a beacon for concern separation across presentation, business, and system logic, VSA takes a different stance. Let's explore the nuances of Clean Architecture before diving headfirst into the world of Vertical Slices, culminating in a hands-on demo to jumpstart your VSA journey with a .NET New project template.

What is Vertical Slice Architecture

Gone are the days of segregating code by mere technical roles – models, views, controllers. VSA champions a paradigm shift, slicing your software vertically, aligning each segment with a specific feature from UI to data storage. It's a clarion call for teams to deliver holistic, user-centric functionalities, fostering modularity and enabling a swift, isolated evolution of each feature – a perfect ally for Agile and DevOps crusaders.

Why Vertical Slice Architecture

The Proximity Principle whispers a simple truth – related changes belong together. Envision a web API's CRUD endpoint revamped under VSA; it's not just about technical layers but about implementation perspective. A vast CRUD landscape peppered with duplicated layers can quickly become a developer's labyrinth. VSA emerges as a beacon, guiding us towards collaboration and simplicity.

How to Implement VSA

Clean Architecture lays the groundwork for a system's resilience against the whims of technological shifts. Let's dissect a request hitting a Clean Architecture endpoint – take the humble Todo Endpoint, for instance.

In contrast, VSA encapsulates all related code within a singular use case or user story. The Todo endpoints are reimagined – each folder, a trinity of presentation, business logic, and database operations.

Templates provided by the VSA NuGet package offer a blueprint, channeling the creation of consistent, grouped folders and files, with shared contexts and repositories. With minimal APIs and the interface-method pattern, the Handler method becomes our conductor, orchestrating the endpoint's symphony.

Harmonizing the Two: A Hybrid Sky

Why settle for one when you can harness the power of both? Infusing Clean Architecture within each vertical slice creates a hybrid architecture, the pinnacle of design, balancing the robustness of Clean Architecture with the agility of VSA.

Conclusion

Vertical Slice Architecture not only enforces consistency but also showcases the elegance of .NET8's capabilities with Swagger and helpful methods. As architects, we're tasked with surveying the landscape, weighing perspectives, and selecting the right tools. Let this journey illuminate your path to architectural mastery, propelling your projects from concept to constellation.