Technical Screen

Matching Queries Against a Log Stream

DatadogSoftware Engineer · Technical Screen · Jun 2026

The first-round problem was query and log stream matching. I was given a stream containing two message types: Q: xxx was a query. Each query needed a unique ID, and I had to output an acknowledgment. L: xxx was a log. For each log, I had to output the IDs of all queries that it completely matched. The example input was: The expected output was: My approach was to use a HashMap

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