标签：#agenticsystems

When I wrote about shifting the engineering process left — spec sessions, autonomous agents, humans reviewing output rather than writing code — a question kept coming up. Where does the Product Owner fit in all of this? It’s the right question. And I think the answer is more interesting than “the PO disappears.” Let’s start with acceptance criteria. We invented them to bridge a gap. The team needed to know when something was done. The PO needed confidence that what got built matched the intent. Acceptance criteria were the contract between the two. But if the Spec Session is where intent gets defined — by the whole team, together, before the agent runs — that gap closes. What the team agreed on in the room is the definition of done. The spec is the acceptance criteria. You don’t need a separate validation step because the planning and the agreement happened at the same time. The tighter the loop, the less ceremony you need around it. There’s a caveat though. The spec is a necessary contract. It’s not a sufficient one. Simon Martinelli’s work on the AI Unified Process validates the spec-driven approach technically. But his model is about the artifact — requirements at the center, AI generating everything else from them. How the team actually builds shared understanding before the spec exists isn’t something it addresses. That’s not a criticism. It’s just a different question. A spec written after a real Spec Session — where the team worked through edge cases together, disagreed, got to resolution — is different from a spec written by one person and signed off asynchronously. Same artifact. Different quality of shared understanding. That distinction matters when the agent hits an edge case the spec didn’t anticipate. So what’s actually left for a dedicated PO? Two things. And they’re very different. The first is product thinking — challenging intent, representing user needs, asking why before the agent runs with something. That’s valuable. But it doesn’t require a ded

An astrolabe doesn’t map every star. It gives you a way to find your position relative to the ones that hold still. That’s the instrument I reach for when someone asks which AI tool they should be using. The honest answer is that the tools will be different in six months. The layers won’t. I spent a week trying to make sense of a handful of names that kept showing up in the same conversations. Tessl . Goose . Archestra . Kestra . Modelplane . RAG , MCP , half a dozen others orbiting nearby. Each one has its own pitch, its own funding round, its own reason it’s the thing you should adopt next. Taken together they read like noise. Taken apart, they sit on different floors of the same building. The agent loop again, the one I keep coming back to. Once you place each tool on a floor, the noise turns into a map. Tessl sits left of the loop , at the intent layer. Turn a spec into something an agent runs against directly. This is the one tool on the list that pushes back instead of going along with it. A well-formed spec is not the same thing as a team that agrees on what the spec means. The Agora produces the second thing as a byproduct of producing the first. Tessl produces the first and assumes the second follows. It doesn’t, automatically. That’s the whole argument. RAG and MCP are plumbing. Protocol, not position. They carry context into the loop and don’t take a side in any argument about who should be in the room when the spec gets written. They’re also the one floor with an actual standard. MCP, A2A , ACP , all under Linux Foundation governance now, joint working groups, cross-protocol commitments. Passing data between systems is a solved problem with decades of precedent behind it, so it standardized almost on contact. Nothing else on this floor plan has that. Governance, orchestration, the harness, the spec layer: every vendor is still building its own version and calling it the obvious one. The standard showed up first at the floor that mattered least to this ar

Anthropic's engineers ship eight times more code than they did a few years ago. And they had to start scheduling lunches so people would talk to each other. Fiona Fung, who leads the Claude Code team, said it on Lenny's Podcast last week. Working with agents all day had started to feel isolating. The team was fast, but they'd stopped running into each other. So they added pairwise programming lunches and hackathons — rituals to put back the thing that used to happen on its own. Eight times the output. Scheduled conversation. That ratio is worth sitting with. Whatever goes missing here doesn't show up in the metrics. It doesn't throw an error. It just quietly stops being available. Here's the part that bugs me most. Ask an AI whether your approach is sound and it mostly tells you it is. Not because it's lying — because it's answering the prompt. No stake in the outcome, no history with the system, no memory of the last three times this exact idea was tried and quietly failed. A colleague pushing back is a different thing. They've got context you never typed into the window, because they were there when it was earned. They're going to maintain this too. They might be wrong — but wrong in a direction you hadn't thought of. An agent can't disagree with you like that. It agrees faster. Same with scope. The agent builds what you ask for, all of it, thoroughly. It won't mention that the third feature is the one nobody will use, or that "good enough" happened two iterations ago, or that something next door already solves most of this. Knowing when to stop comes from someone who's watched a codebase rot under a hundred individually-reasonable decisions. And it only knows what you put in front of it. The person who worked on payments remembers the edge case you're about to recreate. The junior who joined three months ago still sees the thing everyone stopped noticing. That gap — between what's in the window and what isn't — is where the expensive mistakes live. Then the part

I noticed something a few months ago. I was talking less to my colleagues. Not because anything was wrong. I had a question, I described it to an AI, I got something useful back. Why loop in a human if the loop is already closed? It took a while to name what was actually happening. There's a version of the AI story where the interesting work disappears. The agent implements. The spec session produces the plan. Humans review the output. What's left? Ticket hygiene and rubber stamping. Engineering as a series of approvals. I think that's wrong. But I understand why it feels true. Here's what I think is actually happening instead. The agent produces the increment. But the agent doesn't decide what the increment should move toward. It doesn't know whether this library is the right bet for the next three years. It doesn't know which of two implementation approaches leaves options open and which quietly closes them. It doesn't know whether the architectural call made today creates a problem nobody will notice until the system is under load eighteen months from now. That work — giving the project direction, validating trade-offs, deciding what the system becomes — isn't specable. You can't write a ticket for it. And it's not going away. The craft didn't disappear. It moved. Direction is the word I keep coming back to. The agent executes well. It implements against a spec. It generates options when you ask for them. But it doesn't carry a point of view about where the system should go. It doesn't have a stake in the decision. It will implement the wrong architectural direction just as confidently as the right one, if that's what the spec says. Someone has to hold the direction. Someone has to know enough about the codebase's history, the team's constraints, and the product's trajectory to say: not that library, we've been down that road. Not that pattern, it doesn't survive the load we're heading toward. This approach now, that refactor later, in this order, for these reaso

"A fool with a tool is still a fool." — often attributed to Grady Booch I keep coming back to this quote when I watch teams adopt AI. In my last post ( https://schrottner.at/2026/06/18/The-Wrong-End-of-the-Problem.html ) I wrote about shifting the engineering process left — spec sessions, autonomous agents, humans reviewing output rather than writing it. A few people asked the obvious follow-up: if an agent implements and an AI reviews, why do I need a team at all? It's a fair question. And I think the answer is in that quote. The agent validates against your prompt. That's it. If your thinking is muddled, the output will be muddled — just faster and at greater cost. An agent doesn't tell you that you're solving the wrong problem. It solves whatever problem you gave it, thoroughly and without complaint. Most AI usage right now treats AI as a tool. Which means the quality of the output is bounded by the quality of the thinking that went into the prompt. A fool with a tool is still a fool. The tool just makes the foolishness more expensive. The team is the check on intent. Not after the agent has burned three sprints on the wrong thing — before it starts. That's what mob planning actually is, when you think about it. Not a meeting. Not process overhead. It's the place where bad ideas get caught before they get expensive. Where someone asks "wait, why are we building this" before an agent runs with it for a week. But there's something else happening in that room that I think gets underestimated. It's where the learning happens. Not just prompting. System thinking. Architectural patterns. How to decompose a problem. Why a certain approach fits this codebase and another doesn't. How a senior frames a problem before an agent ever touches it — the mental model that makes the output actually good. Right now that knowledge isn't transferring. Everyone is heads-down with their own tools, developing their own habits in isolation. Engineer A gets dramatically better output than

Table of Contents The Integration Problem That Broke Industry 4.0 MCP: The Vertical Connection Layer How MCP Connects to Servers, Tools, and Databases MCP in Real World Industrial Automation ACP: The Horizontal Communication Layer How ACP Works Under the Hood ACP in Real World Industrial Coordination The Six Precise Differences How They Work Together: The Complete Stack Decision Framework for Industrial AI Architects 1. The Integration Problem That Broke Industry 4.0 Industry 4.0 promised connected factories, intelligent automation, and seamless data flow between machines, systems, and humans. The technology arrived. The connectivity did not. The reason is a number called N times M. An enterprise manufacturing facility might have 12 AI agents across quality, maintenance, and planning — and 28 data sources including ERP, MES, SCADA, IoT sensors, databases, CAD repositories, and supplier APIs. Without a standard protocol: 12 agents multiplied by 28 data sources equals 336 custom integrations. Each integration is bespoke code. Each breaks when either side updates. Each requires maintenance. Each represents a point of failure and a security surface that must be independently managed. IBM VP Armand Ruiz stated this precisely: "Without a common standard, every integration is costly duct tape." MCP and ACP together replace 336 pieces of duct tape with two standard protocols — one governing how agents connect to systems, one governing how agents connect to each other. The smart manufacturing market is projected to reach 374 billion dollars by 2025 at 11.8 percent CAGR. Over 50 percent of companies in industrial automation are expected to adopt MCP-based connectivity. The integration problem is not theoretical. The solution is being deployed at scale right now. 2. MCP: The Vertical Connection Layer MCP connects agents to tools and data — the vertical integration layer. It handles the connection between an AI agent and everything it needs to interact with in the external worl