Affirm phone screen, passed the fraud detector round

Affirm phone screen, passed the fraud detector round

Phone screen for Affirm, one round, 60 minutes. Got the fraud detector problem, two parts. First part was debugging an existing PII counter that tracks distinct values like address, ssn, email across events, turned out it was missing a filter on the event type so it was counting stuff it shouldn't. Second part was extending it into an actual detector that flags suspicious events and carries any PII from a flagged event into a future matching set. Lots of starter code to read through first which ate into the clock. Finished with a few minutes left and heard back two days later, moving forward.