Every Monday morning, the CEO would ask the same question: "Show me the lifetime value of a customer who buys a blue sweater after seeing a TikTok ad."
Lena’s first lecture hit him like a bucket of cold water. "You do not have a data problem," she said. "You have a schema problem. You are trying to serve a gourmet meal from a garbage disposal." udemy - data warehouse - the ultimate guide
The CEO asked, "Arjun, show me the lifetime value of a customer who buys a blue sweater after seeing a TikTok ad, broken down by region, and compare it to the same cohort from six months ago." Every Monday morning, the CEO would ask the
And that, Arjun decided, was the ultimate victory. You are trying to serve a gourmet meal
The most painful lesson came from "Type 2 Slowly Changing Dimensions." Previously, if a customer moved from "California" to "Texas," the old data would overwrite the new, erasing history. Lena taught him how to track history. Now, Arjun could see when a customer moved and if their buying behavior changed because of it. The CEO’s blue-sweater-TikTok question was no longer impossible; it was just a simple join.