Demand forecasting is key for the retailing industry. This is especially true in the fashion industry where product demand is volatile and the life cycle is short. In this talk I will describe the Demand Forecasting Problem in the context of a brick-and-mortar retailer. I will discuss commonly used techniques, including evaluation metrics, feature and target transformations and commonly used predictors. Finally, I will conclude with a short discussion on the challenges of successfully implementing a demand forecasting solution beyond the technical details.