Duplicate records are a costly problem in any system that stores people’s names. “Jon Smith” vs. “John Smith.” “Liz” vs. “Elizabeth.” “Renée” vs. “Renee.” To a human, these are obviously the same person. To an exact string comparison, they’re four different records. The fix is to stop asking “do these names match?” and start asking “how confident am I that they refer to the same person?”
This article walks through a practical C# pipeline to do exactly that: normalize input, resolve nicknames, narrow candidates with blocking and phonetics, score similarity with Jaro-Winkler, and apply thresholds to decide what to