Defending Your Junk/Degenerate Design

The interview signal for junk and degenerate dimensions is not drawing the schema. It is explaining why this design is correct. The interviewer will challenge your choices. Having the rationale ready is what separates pattern-appliers from pattern-defenders. Defense Playbook Vocabulary That Signals Seniority The Bridge Move Red Flag Phrases The closing move that ties the whole fact table together: 'So the final schema is: dimension FKs (customer_sk, product_sk, date_sk), one junk dim FK (order_flags_sk), one degenerate dim (invoice_number), and the additive measures (quantity, amount). Every column has a clear role. Nothing is orphaned.' This three-sentence summary hits every rubric item.