When Dimensions Change

What They're Really Testing The interviewer already knows you can recite SCD types 1 through 3. They are testing three things: (1) whether you ask about the business requirement before choosing a type, (2) whether you understand the storage and query cost tradeoffs, and (3) whether you have implemented this at scale and know the operational pain points. The 60-Second Framework Step 4 is the strong-hire signal. Not 'I'd use Type 2' but 'Type 2 for THIS attribute because of THIS business reason, and Type 1 for THAT attribute because history doesn't matter there.' Per-attribute SCD strategy is what separates senior candidates. Why Companies Care Cite these in your answer: At Spotify, wrong SCD strategy on artist metadata caused listener counts to be mis-attributed when artists changed labels.