Data Bricklaying Diary

Sep 2, 2026 · Artificial Intelligence

Why Random Splits Fail for Enterprise Data: Preventing Time, Entity & Business Leakage

This article explains why random row-based splitting creates false generalization in enterprise ML, detailing how to define prediction timepoints, combine business entity grouping with time windows, and implement five-layer leakage checks to ensure test data truly simulates unseen production data.