Lesson 3 - Architecture: Learn to organize your thoughts

AI takes the path of least resistance. That one characteristic explains most of what changed for me about architecting a system once an agent was in the loop. It is genuinely faster than I am on frameworks, patterns, and the standard way to wire something up . Since it has read more on them than I have. But "least resistance" means it optimizes for the thing in front of it, e.g., getting an endpoint to work or a test to pass. It cannot optimize for the shape the system needs for your use case because it does not know all details. You still own 100% of that part. Two ways least-resistance goes wrong Left alone, the path of least resistance breaks in two opposite directions. It cuts a corner to make the immediate thing work: collapses a boundary, hardcodes a value, skips the seam that would have let two pieces move independently later. And when you try to correct it, it will over-engineer and reach for patterns, layers, and abstractions you did not ask for and don't need yet. Both come from the same place: it is solving the prompt, not steering the architecture . Here is the version I lived with. My app is layered the usual way: an API layer, a service layer under it, a data-access layer under that, with clear rules about what each one is allowed to do. Database transactions belong in the service layer. The agent kept ignoring that. Commits I had scoped to the service layer kept turning up in the data layer, or up in the API. The worst one was a transaction that opened in the service layer and got committed two layers down. If left at simple prompts, it will run and deliver you something that works, but you'll find that along the way it has quietly broken the boundary and created a brittle system. Here is the flip side, from just the other day. I was working on a bug fix with the agent on its own branch off main. Mid-test, I hit a separate gap, related to the feature but not the bug, and asked the agent to fix that too. It sensibly put the gap on its own branch, but b