Stop Shipping AI on Toy Datasets: How to Treat Synthetic Data as Infrastructure

The Hidden Contract You Keep Breaking If you are a data or ML engineer, you probably have this experience: • Your service connects to a real database in production. • Your local tests run against a flat file or a couple of mocked tables. At some point, something subtle breaks: o A join fan-outs differently in prod o A constraint that never existed in your synthetic sample explodes o A weird temporal pattern triggers an edge case What changed? You violated an unwritten contract: “The system I tes