Software Architecture: Achieve Conformance, Avoid Erosion, and Ensure Verification

A Practical Guide for Engineering Teams

New to Architecture Verification? This guide explains what software architecture is, and why it is important.

Last updated October 7, 2026

Software architecture is a system's foundational structure: its components, their interactions, and the design decisions that shape performance, scalability, and maintainability.

Conformance matters because code drifts from that intended design over time. This erosion builds technical debt and slows onboarding, so catching deviations early keeps software easier and cheaper to maintain.

Screenshot of Axivion Gravis the built-in graphical modeling and visualization tool

Introduction to Software Architecture

“What is software architecture?” is a question that might have different answers depending on your knowledge, experiences, and use cases. While definitions may differ, certain fundamental concepts are crucial in software architecture. The term “architecture” in software development was initially borrowed from the construction industry due to the similarities between the two fields.

The waterfall methodology was widely used in software development in the past, and detailed plans were required before writing any code. This approach was similar to the planning required in construction, where the architectural design must be finalized before construction begins. But things have changed. Modern software development methodologies are designed to be flexible and easy to change over time, so there’s less need for strict planning at the beginning.

However, the first decisions made regarding how the software is built, can take time and effort to change at a later stage. If you were to ask what software architecture includes, the answer would differ based on their development lens. We will concentrate on the structural aspects of the software and the role of architecture in it.

What is Software Architecture?

Software architecture refers to the overall design and structure of a software system, which includes how its various components interact to achieve the desired functionality — it is the foundation of a software system.

As defined by the ISO/IEC/IEEE 42010 standard (as of Edition 2, 2022), software architecture refers to the core concepts and characteristics of a system within its surroundings, expressed through its components, connections, and the guiding principles of its creation and development.

The standard definition essentially highlights the following points:

When you use software, you might not think about how it’s built. But, just like a building needs a blueprint, software needs a plan too. That plan is called software architecture.

The software architecture is like a map showing how the software works and fits into the world around it. It’s important to make sure the software works well in the environment in which it is used because it minimizes potential disruptions and maximizes the software’s longevity and effectiveness in serving its purpose.
To help everyone understand the software architecture, a description is created that explains how it works and solves the problems it was created for. This description is like a guidebook that helps people see how the software will meet their needs.
Different people care about different things when it comes to software. To ensure everyone can understand the software architecture, different scenarios are created that show how it works from different angles. These scenarios help people see how the software will work for them.

Software projects can vary in the level of attention given to design, time spent, focus, and documentation dedicated to different parts of software architecture.

However, software architecture primarily comprises vital design decisions that significantly influence the system. This foundation is a crucial facet of software development, as it directly affects the quality of software developed on top of it. In other words, it has an impact on the system’s

Performance
Scalability
Maintainability

Simply put, how software is created today must be flexible enough to handle future changes. This means that the software should be designed to make it easy to evolve and adapt to these changes rather than completely rebuilding it from scratch.

Why is Software Architecture so Important?

Before developing software, it’s important to have a plan in place. Just like building a house, the foundation of a software system plays a significant role in its quality — the architectural decisions dictate how the software will function. Having good architectures in place helps increase the chances of success for the software system. It ensures that it can function properly and be easily maintained.

Even small software systems have an architecture, and it’s important to have a good one in place to ensure the system works well and can be easily maintained to make it flexible enough to meet the fast-paced changes in today's world. A well-designed architecture becomes even more crucial with larger and more complex systems.

Architecture mattered before the AI era. But it becomes load-bearing when code volume increases and human review capacity doesn't.
[Read here about 'the Amplifier AI'.]

So, while it’s tempting to start coding right away, planning and designing the software architecture is an essential step in the development process. The benefits of a software system’s architecture with a solid foundation are numerous. Let’s explore these advantages in more detail.

Axivion team explains the cost of late-stage architectural rework or defect-escape cost by phase in one simple diagram

Managing the Presence or Absence of Quality Attributes

The design of a software system is critical in ensuring that it works well and meets the needs of its users. There are certain properties of a software system that can be measured and tested, such as:

how easy it is to maintain
how well it works with other systems
how secure it is
how quickly it performs tasks

These properties are called quality attributes, and they’re critical because they affect how happy users are with the system. Sometimes, different quality attributes conflict with each other, so it’s important to make sure the architecture balances them properly. When the architecture is done well, the system meets all the important quality requirements that its users need.

How Architecture Improves Stakeholder Communication

The good news is that software architecture is designed to be easy to understand for everyone involved, even if they don’t know a lot about technology. Different stakeholders might care about different things when it comes to software architecture. The relationship between software architects and developers is like that between birds flying over a pond and frogs in that pond—the frogs can see the details of their immediate surrounding, but don’t really know much about what happens around them. The birds on the other hand see the big picture, but can’t see any details.

When software is designed, different groups of people have different priorities, e.g.:

The developers focus on implementing their current tasks or features as quickly as possible.
The project managers might be more concerned about making sure it is
available on time and within budget.
The security team worries about making sure the software is secure so that nobody can hack into it to steal important information.

It is the software architect who cares about making sure it’s easy to add new features or fix problems while making sure everyone’s priorities are taken into account. For that, a common language and a shared design approach become even more vital. By doing so, stakeholders can talk about their priorities in a way that makes sense to everyone else and the software can be designed to meet everyone’s needs, while at the same time remain adaptable and maintainable.

This is especially useful for big and complicated software systems that need to be easier to understand. When stakeholders are figuring out what they want from the system and making important decisions, having a formal software architecture can help everyone negotiate and talk about what is needed.

Exploring Methods to Improve the Accuracy of Predicting the Duration and Cost of a Project

From Architecture to Estimate

Project managers need to know how long a software project will take and how much it will cost to plan resources and monitor progress properly. One of the important duties of a software architect is to help project management by providing this information and breaking down the necessary tasks and estimates for those tasks. How the software is designed affects what tasks will be needed for implementation, so the software architect can help project management create the tasks.

Good collaboration between the project manager, software architect, and developers is beneficial for creating accurate estimates. The most precise estimations are attained through team discussions until a mutual agreement is reached. Sometimes, during these discussions, someone on the team provides an insight that no one else has considered, allowing everyone to rethink their position and possibly revise their estimates.

Missed Requirements Cost More the Later They Surface

A well-designed software architecture that accurately reflects the project’s requirements can help avoid costly rework that would be necessary if crucial requirements were missed. Moreover, a well-thought-out architecture reduces complexity, making it easy to understand and reason, resulting in more accurate cost and effort estimates.

Illustrative orders of magnitude from a serial (waterfall) process model; agile practices flatten the curve.
Source: Scott W. Ambler, agilemodeling.com/essays/costofchange.htm

Relative cost to fix one defect, by phase (log scale)

How Architecture Conformance Affects Developer Onboarding

A team that works on developing software often needs to bring in new people as they grow. This can be a challenge, as it takes time for new people to learn how everything works. Apart from that, different people might need to work on the software to fix problems or improve it over time—this is where your software architecture becomes even more important.

Essentially, the architecture and implementation must match to make onboarding easy. The more they deviate, the harder the onboarding gets. Imagine having to explain a fluid plan that changes every time you have a new person on the team. It’s far from ideal. However, if the team has a good plan for building the software and is committed to the original plan, it is easier for new people to learn everything about the software they need to know.

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What is Architecture Conformance Checking?

Architecture conformance checking ensures that a software system is built the way it was designed. It compares the intended architecture with the actual code and flags every deviation. The stronger the deviation, the harder the challenge. Conformance checks make deviations visible the moment they happen.

How it works:
1. Define the target: Describe components, layers, and which dependencies are allowed or forbidden.
2. Extract the reality: Derive the actual dependencies between files, modules, and components from the source code.
3. Compare: Every dependency that breaks a rule is a violation, whether it's an unplanned one in the code or a planned one that's missing.
4. Report and react: Violations show up in the pipeline or pull request, so teams can fix the code or deliberately update the model.

Automated conformance checking is still uncommon, and only a few tools can monitor the health of software systems.

Architecture monitoring helps to make sure that software systems are functioning as they should. Many organizations still go without automated tools, which causes problems later in the software life cycle. This is especially true when building new software on top of old, outdated systems.

When the implementation drifts from the plan, that's software architecture erosion. It happens when developers make decisions that don't follow the original plan or established rules. Each shortcut looks harmless. Together they add up to cyclic dependencies, tangled modules, and code that's costly to change.

What is Software Architecture Erosion

Software architecture erosion (also known as architecture debt) is when software doesn’t turn out the way it was supposed to be designed. When software is created, sometimes shortcuts, temporary fixes, and other compromises are made that can cause problems later on. This can happen when the people building the program don’t follow the rules or make decisions that go against what the program was supposed to do. It’s worth noting that this doesn’t always mean that the developers did a bad job. It might just be that they didn’t know about a certain problem or issue.

Software architecture needs to be verified regularly to ensure it can fulfill its important role. Realistically speaking, you would have:

an architecture
a design
perhaps a detailed design
an implementation
(sometimes with even multiple layers as models etc.)

The challenge of mixing things can happen at each level and has a different impact when that happens. As a result, it introduces technical debt to the entire process. The art of architecture is that the most important decisions at the architecture level make it impossible for the lower levels (design etc.) to mix parts together that should not interact when not deviating from the architecture.

The Impact of Technical Debt

Technical debt can harm the long-term success of software systems by introducing undesirable changes to important parts of the software. This can happen when stakeholders have to make quick decisions to get something done fast or when they don’t have enough knowledge or resources to create high-quality software. For example, someone might prioritize getting a critical function working quickly over making sure the software is designed well.

Technical debt can also happen when design decisions focus on short-term goals rather than long-term quality. These types of technical debt can cause problems with maintaining and improving the software over time. That’s why it’s important for stakeholders to verify their software architecture before making changes to ensure everything is done according to the plan. By doing this, they can save time and money and prevent problems from happening later on.

Architecture Questions from the Daily Grind

What is architectural drift and how can i prevent it in my project?

Software Architecture

Architectural drift is the gradual divergence between the architecture you intended, e.g. layers, module boundaries, allowed dependencies and what the code actually does. It rarely happens through one bad decision but it builds up through small shortcuts.

Closely related is architectural erosion, where the violations pile up until the original design is no longer recognizable. The result is rising coupling, slower changes, harder testing, and a growing cost for every new feature.

How to prevent architectural drift:

1. Make the intended architecture explicit: Document it as a model: components, layers, and which dependencies are allowed or forbidden.

2. Check conformance automatically: Compare the actual dependency structure from the code against the intended model, and run that check in CI so violations fail the build or at least surface in the pull request. This is the single most effective measure, because drift is mostly invisible in code review.

3. Start with a baseline: If your codebase already has violations, freeze the current state and fail only on new ones. Then reduce the existing debt step by step instead of drowning in a backlog on day one.

4. Track structural metrics over time: Cyclic dependencies, coupling between components, and the number of rule violations show the trend before it becomes a crisis.

5. Keep the architecture alive: Update the model deliberately when requirements change, rather than letting the code redefine it silently. Architectural decisions help as much as having clear ownership of module boundaries.

6. Review at the right Level: Add "does this change respect the boundaries?" to your review checklist, and revisit the architecture regularly.

The key principle is that anything not checked automatically will drift eventually. Good intentions and documentation help, but enforcement in the pipeline is what holds the line.

How can I prevent spaghetti code and architectural erosion in a growing software project?

Software Architecture

Spaghetti code is tangled logic inside modules. Architecture erosion is the breakdown of structure between them. Both come from small shortcuts that nobody notices in code review, so the most reliable defense is automation:

1. Define the intended Architecture: Describe layers and components, and which dependencies are allowed, and treat cycles as defects.
2. Check it automatically: Compare the real dependency structure against that model in CI, so violations show up in the pull request.
3. Baseline existing violations: Tolerate the old ones, fail on new ones, and pay down the backlog step by step.
4. Keep units small and interfaces narrow: Single-purpose functions, explicit dependencies and hidden internals make tangling harder.
5. Enforce static analysis and tests: Rules only count if they block merges, and tests make continuous refactoring safe.
6. Assign ownership and track trends: Name someone responsible for the boundaries, and watch coupling, cycles and violation counts over time.

Anything that isn't checked automatically will eventually drift.

How do I enforce an architecture in a C++ legacy codebase automatically?

Software Architecture

C++ makes this harder than most languages but tools like Axivion can help: #include chains, macros, templates and global state create dependencies that aren't visible in the file structure. The approach that works in practice:

Model the target architecture: Define components (mapped to directories or build targets) and the allowed dependencies between them, ideally as a machine-readable file under version control.
Extract the real dependencies from the code: Axivion analyzes your code with a compiler-grade front end and your actual build flags, so it captures macros, templates, calls and type usage that a plain include scan misses.
Compare model and code on every build: Run the check in CI and report violations in the pull request. Dedicated architecture verification tools (such as Axivion Architecture Verification) automate this, and a custom script over include or compile-database data can cover a basic version.
Baseline the existing violations: A legacy codebase will have thousands of violations. Accept the current state, fail only on new violations, and reduce the old ones gradually.
Make boundaries physical where you can: Separate libraries, CMake targets with restricted include paths, and public/private header splits stop violations at compile time.
Treat cycles as the first cleanup target: Breaking cyclic dependencies between components usually brings the largest gain for the least effort.

Expert Tipp to succeed: Start small! Pick two or three critical boundaries, enforce those first, and expand the rules as the baseline shrinks.

Conclusion

An effective architecture serves as a unifying force that connects all parties involved, streamlines operations, saves time and money, and enables early detection of potential design flaws. The architecture is a foundation that binds together different system components, providing a clear development, testing, and deployment roadmap. It creates a shared understanding of the system’s structure, functionality, and behavior, enabling cross-functional teams to work together more efficiently and effectively.

With a well-designed architecture, stakeholders can make informed decisions, adapt to changing requirements, and deliver high-quality solutions that meet user needs and expectations.

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Glossary All Things Architecture

Software Architecture The high-level structure of a system, meaning its components, their responsibilities and the dependencies allowed between them. It defines how the code is supposed to be organized, independent of how it is organized today.

Architecture Conformance Checking Automatically comparing the real code structure with the defined architecture model and reporting every deviation. Axivion runs this in your CI/CD pipeline and checks every commit against your architectural model.

Architectural Drift The slow divergence of code from the intended architecture, caused by many small shortcuts. It is the structural failure that no linter or basic code quality check reveals. The term goes back to Perry and Wolf, who coined both erosion and drift.

Architecture Erosion The gradual decay that sets in when the implemented architecture increasingly violates the intended one. Axivion describes it as creeping in silently, layer by layer, decision by decision. Academic literature adds that the architecture can also become resistant to change.

Architectural Technical Debt The accumulated cost of structural shortcuts, such as forbidden dependencies and cycles, that makes every later change slower and riskier. It is the root cause of technical debt. Gartner warns that 80% of all technical debt will be architectural by 2027.