Onsite

Three-Part Sliding Window Coding Round

OpenAISoftware Engineer · Onsite · Oct 2026

A few days ago I had a technical interview at OpenAI. The coding round had this multi-part problem, so I'm sharing the problem statement and my solution. Part 1: Recent Interaction Count Implement an in-memory, single-threaded chat session analytics service. The input is a live interaction log stream whose global ts is non-decreasing. Each log entry has: user: str, chat: int (unique within each u…

Shared by a candidate · reported Oct 2026. Interview formats change; use it as a guide, not a script.