Where a model's output moves money, decides who gets credit, or has to answer to a regulator. The work that gets a system from a demo to something you can actually deploy.
A model that looks great in a notebook and a model you can trust with real consequences are not the same thing. What separates them is rigour, and rigour is the whole job.
We build decision systems that are accurate, calibrated, explainable, monitored, and robust. Robust against people actively trying to fool them, and against the way the real world keeps shifting under any model's feet. A model isn't finished when it ships. It starts drifting the moment the world it learned from moves on, and our work is keeping it honest after that, not just on launch day.