Welcome to your interview.
The question is on your right: Optimizing Slow Sales Queries. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
Slow SQL queries affect dashboards, reports, and application response times. Interviewers ask this question to see whether you can diagnose performance issues methodically instead of guessing.
Explain how you would optimize a SQL query that is running slowly in PostgreSQL. Your answer should cover:
Keep the answer practical and structured. The interviewer is not looking for deep PostgreSQL internals, but they do expect a clear workflow: inspect the execution plan, reduce unnecessary work, check indexes, and confirm improvements with measurement.