J O H N R A . M E Posts

When a measure becomes a target, it ceases to be a good measure. – Charles Goodhart There is a moment, in the life of every flawed metric, when it stops measuring the thing you care about and starts measuring how badly people want to look good on it. That moment is invisible while it’s happening. You only see it in the rear-view mirror, usually after the budget meeting where someone asks why costs tripled and outcomes didn’t move. This week, 4 of the largest technology companies on earth hit that moment more or less simultaneously (read the article on thestreet.com),…

AI Engineering

AI is shifting the advantage toward people who know what to do, why it matters, and how it all fits together – not just those who go deepest in a single domain. For most of the last century, the career playbook was simple: find a field, go deep, become indispensable. Depth was the moat. Specialists commanded premium salaries, held the door on complex decisions, and were the first call when something went wrong. AI hasn’t made expertise irrelevant. But it has quietly restructured where the leverage lives. “It is tempting, if the only tool you have is a hammer, to…

Engineering

Part 2 of 2 in the “AI Agent Memory” series. Cross-Session Memory with Spring Boot + LangChain4j. Click here for Part 1 of the series. What Is Long-Term Memory in an AI Agent? If short-term memory is the scratchpad (cleared between sessions), long-term memory is the notebook – the persistent, retrievable record of who the user is, what they’ve said across sessions, and what the system has learned about them over time. The naive approach is to dump everything into the system prompt: “Here are all 400 interactions this user has had.” That’s expensive, context-window-busting, and filled with noise. The…

AI Engineering Java Tutorial

Part 1 of 2 in the “AI Agent Memory” series. Short-Term Memory with SpringBoot + LangChain4j. The Demo that wasn’t We got back from our offsite pretty excited. We had just walked through a POC showing how metadata actually earns its keep in an AI-first world. With a solid semantic layer, our analysts could spend more time cooking and less time wandering around the data pantry asking, “where did we put the salt again?” The demo was slick. Agents could find the right data, make suggestions, even tap into technical metadata to build and run queries for users. It felt…

AI Engineering Java Tutorial

It’s a Friday afternoon, and I catch part of a conversation between a couple of colleagues. They’re trying to make sense of what “skills” means for a multi-agent platform we’re planning. One of the engineers (relatively new, but not inexperienced) asked a fair question: “Are we just expected to write a bunch of markdown files?” Engineers coming from Copilot or Claude often get tripped up by the word “skill.” The file, SKILL.md, tends to be the frame of reference. It mean something specific and narrow. The more senior engineer is trying to explain, but it’s not quite landing. The terminology…

AI Engineering