Software Architecture Design with the C4 Model
As a software engineer, you know that software architecture design is crucial to any software project. The C4 model is a popular approach for designing software architecture that provides a clear, concise visual representation of the system’s architecture.
In this article, we will dive into the C4 model and explore how it can be used to create a simple C4 diagram for a given scenario. Whether you are a software architect, developer, or project manager, understanding how to draw a C4 diagram can help you communicate the architecture effectively to stakeholders and ensure that the system is scalable, maintainable, and flexible. So, let’s get started and unlock the power of the C4 model!
C4 Model
A C4 diagram is a type of diagram used in software engineering to represent the architecture of a software system. It consists of four types of diagrams:
- Context diagram
- Containers diagram
- Components diagram
- Code diagram
To get understand the above four diagrams let’s get a simple scenario.
Scenario
An Internet Banking System, Provides all Internet banking functionalities to customers via mobile application or web application. And it consists of the mainframe banking system which stores all core banking information about customers, accounts, transitions, etc. Also, there is an email system to send emails.
Context diagram
Context diagram represents a high-level overview of the system’s environment and external dependencies. It includes things like users, external systems, and other factors that may influence the system’s design.
Let’s draw the context diagram for the above scenario:
Person: Any external stakeholders who interact with the system. These can be end-users, customers, vendors, partners, or any other external entity that is part of the system’s ecosystem. In this scenario, a person will be a personal banking customer.
External factors: This can include anything outside of the system that can impact its design or performance. For example, an external factor could be a regulatory requirement that the system needs to comply with or a third-party API that the system needs to integrate with. There are two external factors in this scenario:
- Mainfram Banking System
- Email System
Container diagram
These are high-level components that make up the system, such as web servers, application servers, databases, etc. Each container should have a clear responsibility and interact with other containers in a specific way.
Let’s draw the container diagram for the above scenario:
Components diagram
A components diagram represents the building blocks of a particular container, representing the software modules or libraries that make up the system. Each component should have a clear responsibility and communicate with other components in a specific way.
Let’s draw the components diagram for API Application Container:
According to requirements, you can draw the components diagram for other containers as well.
Code diagram
This represents the implementation details of each component, such as classes, functions, and modules. This component is not usually included in the diagram, but it is important to keep it in mind when designing the system.
Let’s draw the code diagram for the Mainframe System Facade Component:
This is an optional level of detail and is often available on-demand from tooling such as IDEs. Ideally, this diagram would be automatically generated using tooling (e.g. an IDE or UML modeling tool), and you should consider showing only those attributes and methods that allow you to tell the story that you want to tell. This level of detail is not recommended for anything but the most important or complex components.
Conclusion
In this article, we have explored the C4 model in-depth, including its components, benefits, and best practices. We have also provided a step-by-step guide on how to create a simple C4 diagram for your software system, using a practical example scenario.
Remember that the C4 model is just one of many approaches to software architecture design, and it should be used in conjunction with other best practices and methodologies. By keeping an open mind and adopting a holistic approach to software development, you can design software systems that are both functional and easy to maintain.
In conclusion, the C4 model is a powerful tool that can help you unlock the full potential of your software systems. Whether you are a software architect, developer, or project manager, understanding the C4 model and how to use it can give you a significant advantage in today’s competitive software development industry.
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