What, Harness, How: The Three Layers of AIUP

One of the recurring questions I hear about Spec-Driven Development is this: where does the spec end and the implementation begin? The line is often blurry. Specs leak into class names. Implementation choices sneak into use case descriptions. After a few weeks, nobody can tell anymore what is intent and what is accident.

AI Writes Code. Engineers Build Software.

With Claude Code and similar tools, I do not write much code by hand anymore. The AI does it for me. And most of the time, the result is good. For a moment this looks like the end of an era. If the AI writes the code, what is left for us? A lot. Just [...]

Why in Spec-Driven Development the Spec Must Be Readable for All Stakeholders

In Spec-Driven Development (SDD), the specification is at the center. It is not just a document for developers or architects. It is the shared foundation for everyone who works on the product. And here is the key point: if the spec is only understandable to technical people, SDD misses its purpose.

How and Why to Trace Use Cases and Tests

When you build business software, the same question keeps coming back: why does this code exist? The honest answer is almost always: because some business person needed it. A clinic user needs to register a new pet owner. An accountant needs to close the books. A clerk has to approve a request. Every line of code in a [...]

Use-Case 2.0: The Forgotten Practice That Solves What User Stories Can’t

Many teams today treat user stories as the only way to capture requirements. But there is an older, proven technique that scales better and provides something user stories lack: context. It is called Use-Case 2.0, and it deserves a second look, especially in the age of AI-assisted development.

Why Spec-Driven Development Tools Fail in the Enterprise

The spec-driven development (SDD) movement is gaining momentum. Tools like Amazon Kiro, GitHub Spec Kit, and BMad Method promise to bring structure to AI-assisted coding. And they deliver on that promise, as long as you start from scratch.

A Small App, a Complete Process: Demoing AI Unified Process with a Feedback App

When people hear about AI-assisted software development, they often imagine code generation first. I think that is the wrong place to start.

AI Tools for Developers Are Not Enough

Why are we putting so much energy into tools for the part of software development that is most likely to be automated? Why are we not building much more AI support for the rest of the software development lifecycle?

BMAD vs. Spec-Driven Development: Why AI Needs Better Specifications

AI is not only accelerating coding. It is shifting the center of gravity in software development. Implementation is becoming easier. Specification is becoming more important. Teams that continue to rely on vague requirements may generate code faster, but they will also generate incorrect behavior faster.

AI Makes Coding Cheap. Requirements Are Now the Bottleneck

A recent article by Geoffrey Huntley argues that software development is becoming extremely fast and cheap because of AI. That observation is correct. Code that once took days can now be produced in minutes. Entire features can be scaffolded almost instantly. But this is only half of the story.

A Chief Engineer’s Intuition: Why “Build Integrity In” Is Still the Standard for Excellence in 2026

In my article series, we have now journeyed quite a great deal through the tactical and strategic landscapes of lean software development. In my previous articles, we explored the discipline of “Eliminating Waste,” the curiosity of “Amplifying Learning,” the strategic patience of “Deciding as Late as Possible,” the operational imperative to “Deliver as Fast as [...]

Use Cases vs User Stories – Same Content, Different Outcome

In many discussions, I hear the statement: “Use Cases and User Stories can contain the same information.” At first glance, this sounds reasonable. Both describe requirements. Both describe behavior. Both are used in modern software development. But what happens if we take a real, non-trivial example and try to express it in both forms?