A Streaming Step-Hierarchy Design Problem

The question gives a set of StepProgressEvents, where each event contains: The same step_id can receive multiple updates — for example first running, then later done — and events can also arrive out of order. Each step can have child steps, and in the end you need to maintain and output the current latest step hierarchy, for example: Also, after the initial batch of events is processed, the syste…

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