Count Distinct Active Pins per Time Segment from Overlapping Interaction Logs

Company: Pinterest

Role: Software Engineer

Category: Coding & Algorithms

Difficulty: hard

Interview Round: Onsite

Overview: Given pin interaction logs with start and end times, count how many distinct pins are active in each time segment when the same pin can have many overlapping intervals from different users. Tests interval processing over arbitrary timestamps, deduplication by pin, and precise half-open boundary handling.

Read the full Pinterest Software Engineer interview experience this question came from