How do I lead a school by mission and not just metrics?

You have found the balance that good leaders search for: you use the metrics without letting them run you, and you keep leading for the real work behind the numbers. That is not easy in a system that pushes hard toward the measurable. Holding the mission at the center while still meeting the numbers takes both wisdom and spine. That balance is something you will have to keep choosing, because the pressure to let the numbers become the mission never really lets up. Every year brings new demands to serve the metric first. Staying clear about what the numbers are for, a tool, not the goal, is a discipline, not a one-time decision. Keep naming the real mission out loud to the people you lead, so they know what you are protecting and why. When your teachers see you shielding the human work while still handling the numbers, it gives them permission and courage to do the same. That is how a leader keeps a whole school pointed at what matters. You are doing it. Keep saying it plainly.