For most of my software career I have focused on APIs, distributed systems, hypermedia, and software architecture. My writing, speaking, tool-making, and advising have all centered around improving the design, implementation, and evolution of running systems. I gravitated toward APIs because it was there, most clearly, that design decisions, both good and bad, had a direct and visible impact on the value and quality of software in the real world. It was there that I learned, and eventually taught others, how early choices shape later options or, as I often say, how to get from idea to install.
Looking back over that journey, there are three ideas that connect nearly everything I’ve done over the last fifty years.
Software development is a sequence of translations.
Software architecture is about coordinating translations.
Software engineering reduces manual translation while preserving behavioral intent.
Let’s take each of these in turn...
1. Software development is a sequence of translations.
Every software project begins with a story: an idea of intended behavior. Typically, the phrases “It would be great if we could ...” or “Our customers really want ...” and so forth. There is a set of actions that need to be translated from idea form into something more tangible.
We give these translations different names such as requirements, user stories, data models, API descriptions, source code, test scripts, but they’re all doing the same thing. Each is another attempt to preserve behavioral intent while expressing it in a form suitable for the next participant in the process. This is often referred to as the software development life cycle (SDLC),
Of course, every translation introduces opportunities for misunderstanding, drift, omission, and accidental complexity. And usually these translations are chained together in a sequence. This means the translation of the idea into a user story is one step and then translation of the user story into an API description document (e.g. Open API) is another translation. And that second translation depends on the quality and accuracy of the first translation (idea to story). Translations upon translations is the norm.
Every translation inherits the strengths and the weaknesses of each translation that preceded it.
The challenge isn’t simply writing software. It’s preserving behavioral intent across all the translations in the software development lifecycle. Designers must think not only about each translation, but also about the dependencies that form between translations.
As the cost of generating source code continues to fall, the important question is “Is this code a faithful translation of the behavioral intent that came before it?” And what kind of evidence do you have that each translation along the way continues to preserve and protect the intended behaviors?
Validating behavior preservation requires tooling. Translation is a skill.
And that raises the question: if software development is a sequence of translations, what exactly is the role of software architecture?
2. Software architecture is really about coordination.
If software development is a sequence of translations, software architecture determines where, when, and how those translations and the resulting systems coordinate. And coordination sits at the heart of building effective, available, scalable, and efficient systems (EASE).
Looking back, I’ve come to see the history of software architecture as the history of reducing and reallocating coordination. Whether between data models and object models, services and clients, or people and teams, architecture has always been about deciding where coordination belongs. Amundsen’s Maxim is a haiku on the topic of systems coordination.
Early systems relied heavily on meetings, requirements documents, and manual coordination. Object-oriented methods and UML attempted to coordinate increasingly complex systems through shared models. Service-oriented architectures and APIs shifted coordination into well-defined interfaces. Amazon’s “API Mandate” pushed even further, insisting that teams coordinate through explicit contracts rather than hallway conversations.
After years of thinking about APIs and distributed systems, I’ve come to this definition:
Software architecture is the art of determining where, when, and how coordination occurs so that intended behavior can be achieved while minimizing accidental coordination.
Viewed this way, architectural styles are simply different strategies for managing coordination. I have spent my time on architecture models that favor extreme late-binding (via hypermedia affordances), reduced central control (via composable systems), and runtime adaptation. They differ less in what they build than in how they allocate coordination.
Which brings us to the third idea. Nearly every major advance in our field has reduced the amount of manual translation and coordination required to preserve intended behavior.
3. Software engineering reduces manual translation while preserving behavioral intent.
When I started in this field, I spent hours hand-writing COBOL programs on yellow legal pads, checking logic with truth tables and sequence charts before ever touching a computer. Then I’d wait for an open terminal to type everything in and submit the job to a batch queue. Hours later, I’d finally get the results—hoping for a few pages of successful output instead of a thick stack of compiler errors. Looking back, what strikes me most is how much of software development consisted of manual translation.
Over the decades we’ve steadily reduced the manual effort required to translate ideas into running systems. Compilers eliminated one translation. High-level languages eliminated another. Libraries, frameworks, and cloud platforms reduced still more. AI continues that same trajectory.
Together, these advances reveal a decades-long trend:
Every major advance in software engineering has reduced manual translation without losing sight of behavioral intent.
The work of translation is the work of abstraction; of converting thought into action.
For decades we treated source code as the definitive description of a system. Increasingly, that role belongs to behavioral intent. Source code has become another translation rather than the destination.
As manual translation disappears, evidence becomes more important than ever. The question is no longer who wrote the code. The question is whether the implementation faithfully preserves the intended behavior.
Languages evolve. Platforms come and go. Even source code is becoming less central than it once was. But software engineering has always been, and will continue to be, the discipline of preserving behavioral intent across successive translations.
The real question is whether behavioral intent survives the translation.
Closing
While I am best known for my work on web APIs, I have always thought of it as part of a broader effort to improve the way we design, build, and evolve software. REST, hypermedia, CSP, GRAIL, TRAM, and now AI coaching are simply different explorations of the same underlying question:
How do we preserve intended behavior while requiring less manual translation and less unnecessary coordination?
That question has shaped my work for almost than fifty years. I don’t expect it to stop now.
