Over the past few months, I’ve been investing a lot of time building agentic development workflows for real production environments. Not only prompts. Actual operational environments around agents. Things like skills, execution tooling, validation layers, testing flows, memory handling, Git integrations, and constrained execution paths. One thing became very clear very quickly. Using agents in legacy or mission critical systems without a proper harness can become dangerous surprisingly fast. Especially in financial systems. Even with specification driven development (SDD), detailed tasks, and explicit instructions, I noticed a recurring problem. The agent would correctly implement the requested functionality, but at the same time introduce large unintended changes across the codebase. Not because the model was “bad”. But because the environment still gave it too much freedom. A small business change could suddenly trigger a massive refactor in tightly coupled parts of the application.…