What Is Software Architecture: A Complete Guide to Building Robust Systems

One of the problems development teams experience is that when they build applications, they are unable to scale them or handle maintenance and that leads to technical debt and maintenance nightmares. Eventually, the very thing that is software architecture becomes necessary once an organization needs systems to continue to evolve, scale, and change because of the needs of the business.

Software architecture is what provides the fundamental structure for resilient systems, establishes how the components interact, and ensures what is architectural design in software engineering aligns with both what the business wants and is technically possible. Having an overall structure created with purpose around foreseeable use cases helps minimize expensive redesigns and provides a platform for success.

What is Software Architecture?

Software architecture is the high-level structure of software systems. Software architecture encompasses how the components are arranged, how the components relate to one another and the guiding principles that will govern how the system will evolve. Software architecture represents the blueprint that turns business needs into technical solutions.

The architectural design process will involve making decisions about how the system will be organized, what technology will be used, how the components will interact, and so on. Those decisions will impact system performance, system maintainability, system scalability, and operational sustainability.

Modern software architecture also extends to cover how the components are deployed, how the components will run as a viable operational solution, and the design of the broader infrastructure that wraps the system, all of which are essential in helping the system or solution meet its functional and non-functional requirements effectively.

Software Architecture Definition

Software architecture is the building blocks of a system with respect to their components and relationships to each other and the environments in which it operates, as well as the principles that govern its design and evolution. Therefore, architecture can be thought to include the structure and behavior of the systems they are designing.

Software architecture lays out constraints and rules that future design decisions need to take into consideration. It creates shared terminology among stakeholders and can also be treated as the primary artifact that describes the system’s design intent.

Key Characteristics of Software Architecture

Structural Architecture Characteristics

Structural Architectural Characteristics Structural characteristics define the physical and logical structure of system components. Structural characteristics include, but are not limited to, modularity, component coupling, levels of cohesion, and system topology which determines the relationships among systems parts.

Structural characteristics should promote understanding of the system, allow for parallel development, and ease the process of maintenance activities. Poor choices regarding structural characteristics create bottlenecks to the speed and quality of development ability.

Operational Architecture Characteristics

Operational characteristics focus on how the system behaves at runtime. Examples of operational characteristics include performance, scalability, availability, or reliability requirements. Operational characteristics affect user interaction and business outcomes.

The operational characteristics of architecture need to be addressed within the architectural design and do not get addressed or added in later. Considerations will include capacity, fault tolerance models and monitoring approaches to ensure that the systems health is supported.

Why is Software Architecture Important?

Architecture matters because it sets the stage for all the ensuing development activities. Early architectural decisions shape the future of programs, and become contributors to more decisions as the system ages - resulting in changes that can often be a central tenet of cost.

Good architecture allows teams to use its foundations to leverage ways to deliver features quicker, improved system quality, and allow teams to communicate in effective ways to adapt evolving requirements rapidly. Essentially, it allows the basic foundation for improvement to occur not only at the system level, but also for an evolving enterprise - and ultimately scale.

Advantages of Software Architecture

Architecture that is done properly entails a great number of benefits, and includes an increase in system quality, reduced development costs, improved team collaboration, and system maintenance longevity. Proper architecture also allows organizations to pursue a rapid in response to market and technical changes.

Architecture also provides effective communication to stakeholders, a justification for the decisions made, a standard to develop cost-effective processes for three distinct teams.

Architecture Activities

Primary Architecture Activities

The architecture required to contain, tackle, and resolve engineering concerns leading to defects in requirements includes; analysis of requirements, decomposition of the system, definition of concepts for components, interfaces, and applications, and evaluation of the architecture. This defines the systemic architecture: a fundamental decision, considering behavior and structure is architectural concerns.

Each activity will yield an artifact that informs the organization of the particular dimension to continue investment. The architecture development process is more than a function of linear thought to a linear perspective. The architect is encouraged to engage the architect in an iterative process that leads to refinement of decisions in deference of change by fostering a culture of responsiveness to requirements and technical knowledge.

Architecture Supporting Activities

The secondary architecture activities consist of; documentation, engagement of stakeholder in dialogue, identifying new technology that promotes development, or codifying considerations needed to deem the architecture in tune with governance. The latter engages the stakeholders whom require an architraves. The different dimensions of decision-making, governance, policy, all served to maintain and remediate architectural decisions as close to correct as the initial decision made.

Documentation activities generate artifacts that capture architectural knowledge and help onboard new team members. Communication activities ensure that all stakeholders receive the same understanding of architectural decisions and their consequences.

Software Architecture Design Strategies

Decomposition Strategies

System decomposition involves breaking up large and complex systems into smaller manageable components ("Sub-systems") with solid boundaries and responsibilities defined. There are functional, layered, domain-driven (strategic, tactical) decomposition strategies among others.

All decomposition strategies have pros and cons that affect complexity, maintainability and organization of team structures. The decomposition strategy should be based on the system requirements, team structure and organizational requirements.

Integration Strategies

Integration strategies define how the system components communicate and coordinate their work (synchronous, asynchronous, data-sharing patterns, error-handling etc).

Modern integration strategies espouse loose coupling, fault tolerance and scalability to accommodate and support distributed system sizing and microservices architectures

SOLID Principles of Software Architecture

Single Responsibility Principle

Each architectural component should have only one reason to change, focusing a single business capability or technical concern. The single responsibility principle simplifies complexity and thus maintains the lifecycle of the system.

Having components that have a single responsibility also helps facilitate better organization of teams and their ability to work in parallel on development activities across the system.

Open-Closed Principle

Make components open for extension but closed for modification. The single responsibility principle also helps facilitate the ability for a system to evolve without changing stable (and previously changed) components.

Architectural patterns like plugin architectures and dependency injection support this principal by allowing new functionality to be added in various ways outside of core changes.

Additional SOLID Principles

The Liskov Substitution, Interface Segregation, and Dependency Inversion principles influence component design and interaction patterns at the component level. Following these principles promotes adaptable adaptable architecture that is responsive to changing requirements.

At the architectural level they inform design, API conventions, and patterns of interaction of components, e.g., in the context of distributed systems.

Application Architecture

Application architecture refers to a specific application's internal structure focusing on how components are organized, how they communicate and how they contribute to a user's experience. It is shaped by how the application defines and delivers specific business capabilities.

When considering application architecture, prevalent contemporary concerns include responsive design, progressive web applications, and mobile first design assuring the same experience is available across platforms and devices.

Microservices Guide

Microservices Architecture Principles

Microservices provide and pattern applications as bundles of small autonomous services which communicate and interact through well-defined APIs. Each service owns its data and can be developed, deployed, and scaled independent of others.

By composing applications as microservices, there is capacity for heterogeneous technology, team autonomy, and rapid delivery. However, they introduce a level of complexity in service cooridnation, data consistency and overall operational management.

Microservices Implementation Strategies

For successful microservices implementation, there must be clear boundaries to define the services, effective communication patterns, and effective monitoring strategies. Service discovery, load balancing, and circuit breaker patterns become integral.

Containerisation technologies and orchestration frameworks provide the necessary infrastructure foundation for microservices to be deployed and managed in production.

Software Architecture Design Tools

Modeling and Documentation Tools

The purpose of architecture design tools is to help visualize system structure, document design rationale, and help communicate projects to stakeholders. Architecture design tools can be as simple as diagramming software or as complex as fully functional modeling environments.

There is a plethora of tools readily available. There are suite of enterprise architecture tools, UML modeling tools, and simple lightweight diagramming programs with collaborative design functions and version control integration.

Analysis and Validation Tools

Architecture analysis tools enable software architects and other designers to validate design decisions and ensure they address quality attributes, and highlight issues before they are built. They can support performance analysis, dependency analysis and architecture debt analysis.

Static analysis tools, architecture testing frameworks, and simulation environments allow architects to continuously amend their decisions and make changes to the architectural design.

Software Architecture and Agile Development

Architectural Evolution in Agile

Architectural Change and Evolution in Agile Development Much like the development through agile and iterative delivery on the need to respond to change, in some ways architecture is closely aligned having to focus on an evolutionary architecture which can allow for some architectural decisions to be made incrementally and changing them for new requirements as they arise.

Evolutionary architecture practices comprise architectural spikes, proof-of-concepts and architecture reviews that enable design decisions to remain continually aligned with changing business conditions.

Balancing Architecture and Agility

Agile projects are successful when they find the right balance of architectural planning upfront and allowing evolution. This is done by differentiating architectural runway elements, setting standards to be followed and maintaining architectural integrity during the iterations.

Cross functional teams with embedded architects are better able to embed architectural decision making into agile planning and delivery activities.

Software Architecture Topics

Emerging Architecture Patterns

Current architecture patterns include cloud-native architectures, serverless computing, event-driven architectures and edge computing patterns. These patterns support modern needs for scale, resiliency and cost effectiveness.

By recognizing emerging patterns, architects can make informed technology decisions by leveraging the enablement offered by modern platforms/technologies within their designs.

Architecture Governance

Architecture governance provides the processes, standards, compliance and oversight needed to ensure that architectural decisions align with organizational goals and technical standards.

Governance activities in architecture would be activities like architecture reviews, compliance assessments, and knowledge sharing activities that helped to maintain architectural consistency across multiple projects and teams.

Related Resources and Further Reading

Continue Exploring Software Development

Expand your knowledge of software development practices and methodologies through these resourceful links:

Understanding Software Development Phases - Read more about the full software development lifecycle, including planning and analysis, production and deployment and maintenance. This guide will cover background information helpful for understanding architecture, and how the architecture acts in the larger development context.

Top CI Tools for Efficient Software Development - Understand how continuous integration tools support architectural decisions and allow you to create more robust deployment pipelines, as well as discover tools that would help preserve architectural integrity during the software development lifecycle.

Software Development Best Practices and Insights - Read through our library of software development articles that include advanced topics, new trends, opinions and practical implementation strategies, or as a supporting reference for your architectural planning effort.

Software Egg Explained: Development Fundamentals - have a firm understanding of the principles associated with the fundamentals of software development. These principles are key to impactful architecture decisions and systems design.

Conclusion

Software architecture is the foundation of success software systems. Software architecture affects everything from the productivity of developers, to a software system's reliability, to the agility of a business. By understanding the nature of software architecture and mastering it's key characteristics organizations can create systems that deliver consistent value.

The importance of software architecture extends beyond technical considerations to include business strategy, team organization, and operational efficiency. Investing in architectural capabilities provides lasting competitive advantages in rapidly evolving technology landscapes.

Today's architectural practices are evolutionary by nature, therefore they strike a balance between front end design and iterative design that allow the system to adapt to changing performance requirements, but still ensure that systems security and operational excellence are maintained.

Frequently Asked Questions (FAQs)

What is the difference between software architecture and software design?

Software architecture primarily focuses on the overall system architecture, the relationships between the various components, as well as the fundamental design principles that are applicable to the overall system. Software design focuses on important details such as the algorithmic approach and implementation details, which occur at the code level in each of the components.

Architecture prescribes the structure and constraints that guide all design decisions, and design implements the specific functionality and performance in those structural constraints.

How does software architecture relate to system architecture?

Software architecture would be a subset of the system architecture by addressing the software components and their relationships. In other words, system architecture contains all components of the complete system including the hardware, its network infrastructure, the software, and the operational processes and procedures.

Architecture and design share similar principles, but operate within different levels of abstraction, with different scopes addressing challenges that occur within the broader system.

What knowledge skillset would a software architect need?

A software architect needs to have a solid technical background with various programming languages and architectural patterns, and possess skills in understand system design principles. A software architect also needs effective communication skills to liaise with various stakeholder groups and direct their development teams in the same direction with a clear knowledge vision.

To architectural success, business acumen, strategic/long-range thinking, as well as a balanced determination of technical trade-offs and business needs are all equally important.

When should you start thinking about software architecture?

Some architectural considerations may be considered as far back as the earliest project phases, ideally, in requirements gathering and system planning activities. These early architectural decisions create foundations, that become increasingly costly to change thereafter.

That said, architecture should be an iterative and evolving happenstance throughout the project development lifecycle, as new requirements and new operational learnings derived from the development process will shape and inform it.

What are the most common software architecture mistakes?

Common software architecture mistakes include: 1. over-engineering solutions; 2. ignoring non-functional requirements; 3. creating overly closely-coupled components; and, 4. improperly documented architectural decisions.

Additional common mistakes, include: 1. adopting the wrong technology - scope changes, for example, can significantly constrain development; 2. neglecting to plan for scalability; and 3. making architectural decision without consideration of operational requirements.

How do you measure software architecture quality?

Measuring quality in architecture can be determined through means including: 1. system performance measurements; 2. maintenance or maintainability scores; 3. coupling characteristics or measures; and 4. architectural principles and standards compliance measures.

To qualitatively determine quality in architecture measures can inlcude: architecture reviews, stakeholder satisfaction measures, and/or measures against quality attributes like scalability, reliability, and/or security requirements.