"What Happens When the Source Adds a Column?"

What They're Really Testing The Unlock Schema evolution is not about handling every possible change. It is about defining which changes are safe (non-breaking) and which require coordination (breaking). A new nullable column is safe. A type change from string to integer is breaking. The pipeline should handle the first automatically and alert on the second. The 60-Second Framework Why Companies Care At Spotify, a Protobuf field type change from int32 to int64 in the listening events schema broke 14 downstream consumers simultaneously. At Airbnb, a column rename in the booking source table caused the booking pipeline to produce NULL values for 6 hours until an engineer noticed. At Netflix, schema registry enforcement prevented 340 incompatible schema changes from reaching production in a si