What About Schema Changes?

Concepts: paSchemaEvolution

Your incremental pipeline is running smoothly. Then on Tuesday at 2 AM, the backend team adds a new column to the source table. Your pipeline either crashes, silently drops the new column, or - if you are lucky - handles it gracefully. The interviewer who asks "what about schema changes?" is testing whether you have experienced this pain. Your answer should prove that you have. The Schema Change Taxonomy Not all schema changes are equal. The interviewer wants to hear you classify them by impact level, not treat them all the same. Adding a column is almost always safe. Dropping or renaming a column can break every downstream consumer. Senior signal: mention that changing a primary key requires a full rebuild, and that most teams underestimate this. Schema Registries A schema registry is a v