Designing Embedded Software Architectures That Last

I've reviewed hundreds of firmware projects over the years, and one thing always stands out: the most successful projects have a clear, deliberate architecture.

- By Jacob Beningo

The rest start fast, look great for a few sprints, and then slowly collapse under their own weight. Sure, they have the right processes in place, and the developers have the right skills and tools, but they are missing something critical to their success: an architecture.

IEEE 1471 defines software architecture as “the fundamental organization of a system embodied in its components, their relationships to each other and the environment, and the principles guiding its design and evolution.”

Architecture is the blueprint of what you're building. It’s the roadmap that tells you how to get your system to the desired state. It’s the decisions you wish you could get right early in a project.

Architecture isn’t about drawing boxes and arrows—it’s about clarity. Clarity of purpose. Clarity of flow. Clarity of design. In embedded systems, clarity is everything. It’s what keeps firmware maintainable, testable, and scalable as products evolve.

Yet too often, teams skip architecture because they think it’s “extra.” It’s not. It’s the foundation that holds everything together.

For those who do think about architecture, it’s not uncommon for them to think of it as the structure of their software. Over the years, I've learned that architecture isn’t one-dimensional. It’s not just structure. It’s built on four interconnected parts which guide how we design and evolve software.

Today, we will explore the four critical pieces you must consider when designing a software architecture that survives the test of time.

In this article, we'll walk through:

• What software architecture is and why it matters

• Software Characteristics—what your system must be

• Design Philosophy—how you think about building it

• Architectural Decisions—why you chose a path

• Structure—how everything fits together

When you understand all four, you stop reacting to problems and start engineering solutions that last.