How would you reduce the number of duplicate leads and contacts being created in Salesforce?

I would configure matching rules that define when two records are considered duplicates, and duplicate rules that alert or block users when they create or edit a record that matches.

I would also look at the sources of duplicates, such as web forms and integrations, and clean existing data with duplicate record reports and merge tools.

The interviewer expects matching rules and duplicate rules and the difference between them. Good answers also address root causes and existing duplicates. A pitfall is relying only on unique fields, which is too rigid for names and emails entered in different formats.