What are some famous software architecture patterns and how to make the right choice?

The whole ecosystem for software development has changed significantly in the last decade. Nowadays, the software is developed using Agile methodology,  laced with NoSQL databases, deployed on Container+Cloud using CI/CD, rendered on a modern browser or smartphone, and the machines communicate with each other via a high-speed network. 

The complex software solution bracing up for a new technology revolution, and also software maintenance, and enhancement tasks have become time-consuming and tedious. For rapid software development; however, software patterns come as a soothing factor for developers, software architects, and operators. 

The software architecture helps to add new features to existing software since the architecture is already in place. It helps you to identify risks early on in the process. The application or software success depends on the selection of architecture patterns.

It is similar to building a house where the choice of house and interior is based on the weather or geolocation.  For example, you may create an insulating house for a cold region while you may build a ventilated house for a temperate zone.  Likewise, software development architecture also varies depending on the complexity of app features. 

Characteristics of good software architecture

• It should be easy to maintain when bugs are detected
• It should be flexible, extensible, and usable in the long term
• It should adapt to requirements
• It should be scalable and refactoring should be easy
• It should not decrease the performance while adding features
• You shouldn’t find repetition in the code

Some famous software architecture pattern includes,

• Microkernel Pattern
• Microservices Pattern 
• Layered Architecture Pattern
• Event-based Pattern

1)  Microkernel architecture pattern

The Microkernel architecture pattern is referred to as the plug-in architecture pattern. It is a natural pattern for implementing product-based applications.  The Microkernel architecture pattern has two types of architecture components: a core system and plug-in modules. The central unit of the Microkernel architecture pattern defines general business logic, and it makes the system operational. Whereas, the plug-in modules are standalone modules that contain additional features, specialized processing, and custom code empower the core system. One big benefit of the microkernel architecture pattern is that it can be embedded or used as part of another architecture pattern.

The microkernel architecture is best for applications like,

• Applications that fetch data from different sources transform that data and writes it to different destinations
• Task and job scheduling applications

2)  Microservice architecture pattern

Microservice is based on the concept of building a small program that works together for any application. The microservice allows the developers to create an application module independently. They can be deployed independently, and together they fulfill the business objective.  With a microservices architecture, it is easy to implement new technology and process adoption. The application is segmented into smaller chunks, which makes it easy for developers to develop and maintain.  

The microservice architecture is best  suited for applications having, 

• Applications with small components
• Rapidly developing new businesses and web applications
• Development teams that are spread across the globe 
• Apps dealing with high-volume data 
• Apps having low-value data that can be lost occasionally 

3)  Event-driven architecture pattern

It is a popular distributed asynchronous architecture pattern used to produce highly scalable applications. Event-driven apps can be created in any programming language. It is highly adaptable and can be used for complex as well as small applications. In an event-driven architecture, different components interact with their environment by means of consuming and producing events or commands, which are often packaged as messages and sent over the network.  The event-driven architecture builds a central unit that accepts all data and then delegates it to the separate modules that handle the particular type.  It is a relatively complex architecture to implement compared to other patterns.  Event-driven architecture can complement service-oriented architecture (SOA). It is recommended for business applications that interact with common customer segments but sell different products and services.

The event-driven architecture is best suited for,

• Applications handling large volumes of complex real-time transactions
• Application that requires asynchronous service communication

4)  Layered architecture pattern

The layered pattern is the most common architecture pattern. It is the traditional method for designing most software. In a layered architecture, all the components are interconnected but do not depend on each other. For example, the presentation layer is responsible for handling all the user interface and browser communication logic, while the business layer deals with the execution of specific business rules associated with the request.  

The layered architecture is best suited for applications having,

• Applications that need to be built quickly
• Applications that need to adopt traditional IT departments and processes
• Teams that are not used to other architecture patterns 
• Applications that require strict maintainability and testability standards

There are other architectures like serverless architecture, space-based architecture, MVC model, and so on that are quite popular among software developers.