How Small Evaluation Mistakes Lead to Big Production Failures
How Small Evaluation Mistakes Lead to Big Production Failures Introduction Machine learning evaluation often looks simple on the surface. Split the data, train the model, calculate metrics, and compare results. If the numbers look strong, the model is considered ready for deployment. However, many production failures do not originate from weak algorithms. They begin with small evaluation mistakes that go unnoticed during development. These minor oversights create inflated confidence, hide structural weaknesses, and allow fragile models to move into real-world systems. In practice, a model rarely fails because it cannot learn patterns. It fails because it was evaluated incorrectly. Understanding how small evaluation mistakes lead to large production breakdowns is critical for building reliable machine learning systems. The False Comfort of a Single Train-Test Split One common mistake is relying on a single train-test split. While this approach is simple, it introduces randomness in...