What is software architecture?

It seems simple: software should be intuitive, easy to use, and designed to help you meet your technical and business goals. But as soon as you dig deeper on the backend, you’ll likely uncover a complex web of components and processes, all working together to keep things running. To navigate the challenges of software design—and to reap the most benefits—it’s important to plan ahead.

That’s where software architecture comes in. Software architecture refers to a set of fundamental structures that developers use as an overarching visual guide when planning for and building out software solutions. These frameworks also ensure that a project meets its technical and business needs by planning for important functionality such as scalability, reusability, and security. These plans are then broken down into individual components and code during the design phase.

Let’s explore an overview of software architecture—and software architecture design—and its many strengths and applications.

Key components of software architecture

At its core, software architecture is made up of interchangeable building blocks called software components. Software components come in the form of packages, apps, or services, and they feature data that can be plugged into a larger system framework.

These components can also be connected to each other through their respective programming interfaces. By delivering data from one interface to another, components communicate with each other to form a relationship, a system, or a grouping of systems.

An architecture style helps define how these systems are patterned, organized, and used in tandem with each other, forming a cohesive design system that can then be referred back to throughout the entire software development lifecycle (SDLC). And by templatizing these styles, they can be reused and reapplied to a variety of apps and solutions.

Benefits of good software architecture

Good software architecture design can help your organization:

• Easily scale up or down through agile, iterative updates.

• Maintain code quality, reduce errors, and find bugs.

• Modernize legacy systems, reduce audit and IT costs, and build innovative new customer experiences.

• Streamline development through reusability and automation, in turn saving time and boosting productivity.

• Reduce costs, speed up time to market, and boost customer satisfaction.

• Optimize the overall performance of your software.

Challenges of software architecture

In contrast, poorly designed software architecture may:

• Make it difficult to effectively manage interactions between components.

• Leave your software vulnerable and open to security risks.

• Increase the cost of initial investment.

• Result in overly complex, overly engineered systems.

• Be too inflexible to adapt to changing scenarios, technology, and requirements.

• Contribute to performance bottlenecks.

• Create communication issues between architects, developers, and users.

• Result in outdated, difficult-to-maintain architecture, contributing to a lack of integration capabilities.

• Make it difficult to scale up and down without major architectural changes.

• Require the dedicated skills of an entire software team to fix or maintain it.

Common architectural patterns

Monolithic

A monolithic architecture is a traditional type of architectural style where a single container houses every component, service, and function that make up an application, resulting in lower costs, higher performance, and a simpler design. In the container, all the components are merged, which means they share the same codebase and are managed, processed, and deployed in a single, large file.

Monolithic apps must be deployed in their entirety as a single unit, which means that updating or adding features to the codebase requires redeploying the entire app. This poses a challenge in terms of scalability. As a result of that, a monolithic architectural style is best suited for simpler, more general-purpose apps.

Microservices

A microservices architecture takes the monolithic structure and breaks it down into containerized collections of small, loosely bundled distributed services. Each service is autonomous, has its own separate codebase or external state, and has its own responsibilities within the context of the system, though they can also communicate with other services. By breaking the app down into smaller parts, developers can better update, test, and manage code.

Microservices are considered foundational to modern app development and can be found in many major service-oriented apps, including streaming services and rideshare services.

Client-server

In a client-server pattern, the client, also known as the host, sends a request for data, apps, specific services, or other resources to a remote computer, or a server. The server then accepts the request, processes it, and delivers the resources back to the client.

This type of architectural style is best suited for email services, websites, file-sharing apps, or any other type of service that benefits from a call-and-response model.

Layered

Also known as N-tier, a layered pattern divides an app into layers that perform specific functions. These layers are only able to communicate with the layers that sit directly below them. For example, a typical web application may be comprised of four layers: user interface or presentation, business, application, and database. In this situation, the presentation layer can only interact with the business layer, but not vice versa.

Layered architecture simplifies development, testing, and maintenance as each individual layer can be updated or modified without affecting the layers beneath or above. It is the most widely used pattern among enterprise apps, especially among major ecommerce apps.

Event-driven

An event-driven architecture is modeled around the recording, dissemination, and processing of events—actions or triggers that a user takes in an app that can cause a change in state, which the system recognizes in near real time—by communicating with decoupled services. The framework consists of event producers, which capture the event, as well as event routers, which transmit the events to consumers.

Event-driven architecture is ideal for ecommerce websites with frequent user interaction, such as when a user fills a signup form or adds an item to their cart.

Design principles and best practices

Now that you’re acquainted with some of the most widely used software architecture patterns, you’ll want to consider the following design principles and best practices to help you apply them effectively:

SOLID principles

Founded by software engineer Robert C. Martin, SOLID is an acronym that refers to a set of five object-oriented design (OOD) principles to follow when developing software. By adopting SOLID principles, developers can ensure that their project remains scalable, iterative, extensible, and bug-free.

SOLID stands for:

• Single-responsibility: The single-responsibility principle states that a class—a template for grouping objects together—should only have one purpose or responsibility, and all its properties should serve that purpose.

• Open-closed: According to this principle, software objects, classes, or modules should be open for extension but closed for modification. An object can be extended without ever actually touching a piece of code.

• Liskov substitution: Developed by computer scientist Barbara Liskov, the Liskov substitution principle states that interfaces should be substitutable, and that subclasses should be replaceable for their main classes.

• Interface segregation: This principle states that interfaces should be broken down into smaller, more autonomous parts for the purpose of minimizing code errors and repetition.

• Dependency inversion: According to the dependency inversion principle, low-level modules can easily get swapped out for other low-level modules without high-level modules being affected.

Separation of concerns

The separation of concerns principle states that different parts of software should address different concerns. For instance, an app featuring a layered architecture is composed of four different layers—presentation, business, application, and data—with each layer fulfilling a different function for the software.

Modularity and encapsulation

Encapsulation is a principle that states that components should manage their own behaviors and states, emphasizing easy bundling and loose coupling. Through encapsulation, different parts of software are self-contained and insulated from other parts of the app, allowing each component to operate autonomously. Encapsulation establishes modularity in app design, since objects and functions can be easily replaced with other modules—so long as they share the same interface.

Design patterns

Much like software architecture patterns, design patterns are reusable frameworks that allow you to build software faster and more efficiently through the templatization of code. While software architecture plans for the overarching structure of the solution, software design breaks the app down to the component level. Some popular design patterns include the singleton, the adaptor, and the proxy, though there are dozens to choose from.

Tools and technologies for software architecture

Unified modeling language (UML)

The unified modeling language (UML) is a standardized visual modeling language for software design and development. As a visual language, UML uses diagrams rather than code to map out the structure of a software system, how it should behave, and how each of the components should interact with each other.

Architectural modeling tools

Architecture modeling tools help architects visualize, define, and document software architecture through graphical code rendering, or models. Models provide architects with a clear module-by-module breakdown of an app’s functionality. With the help of modeling tools, it’s easy to create and maintain models throughout the software development lifecycle.

Version control and collaboration tools

Version control systems and collaboration tools provide users with the ability to share code, track changes, manage conflicts, and work with teammates. This, in turn, fosters a culture that emphasizes collaborative software development. Version control tools allow for a more efficient workflow, higher quality code, and greater productivity overall.

Conclusion

A solid foundation with clearly defined goals is pivotal to the success of every development project. To navigate the complexities of software, it’s important to have a well-organized blueprint as your guide—which is why software architecture and design should always be a top priority for every team and organization.