Never optimise code you cannot test. An energy fix that changes what the code does is a bug. And a lot of old code has no tests at all. So nobody can check the optimisation. And nobody dares to merge it. A saving bought with a broken feature costs far more than it saves. Here is the fix you can use today. Before you change anything, write tests that pin down what the code does now. Run the full test suite before and after every optimisation. Keep public interfaces the same, unless you mean to change them. GreenCode researchers put one rule first: never break the code to save energy. GreenCode's Constitution skill can guide an AI coding agent to fix waste safely. Then catch new bugs and security issues, using tools like SonarQube. GreenCode helps tackle this by writing the missing unit tests before it changes code. Then no change may raise quality issues, security flaws or errors. That was GreenCode Tech Tip number thirty-four. Follow for the next tip, and find more on greencode.ai/tech-tips.