In recent years, "sourcers" are the ones who email / call engineers on behalf of the recruiters. They are part of the recruiting department.
Article says:
"Levy previously told Insider she was hired on Meta’s Sourcer Development Program, a 12-month program that helps workers from underrepresented groups enter the corporate technology recruiting industry."
Article says:
"Levy previously told Insider she was hired on Meta’s Sourcer Development Program, a 12-month program that helps workers from underrepresented groups enter the corporate technology recruiting industry."