Turning databases into reward functions is a neat instance of the broader verifiable-rewards trend: executable queries give you cheap, objective grading at a scale no human labeler or reward model can match. The Hugging Face team is right to hunt for signal sources that don't need preference data, though the open question is generalization — agents optimized on deterministic, well-specified tasks may struggle in the messy environments where agents actually earn their keep. Still, this is exactly the kind of infrastructure work that compounds if the pipeline is open and reproducible. Worth watching whether database-grounded rewards become a standard post-training ingredient rather than a one-off trick.