Incident
An unplanned event that degrades a live service for users, from a slow page to a full outage.
What it tells you about a developer
How a candidate narrates an incident reveals more than most interview questions. Strong engineers describe restoring service first, then communicating status, then the systemic fix that followed. The shape of the story tells you what kind of team they came from.
When live software breaks, the team declares an incident and works a defined process. First they assess how bad it is, then they restore service, then they find the cause. Severity labels like SEV1 or P1 mark the worst cases. Afterward, mature teams write a postmortem documenting the cause and the prevention, and it assigns no individual blame.