Interview Guides
You are given delivery event data for Lucid Studios and asked to analyze monthly delivery performance by studio. Write a PostgreSQL query that returns one row per studio per delivery month, showing the average dwell time in hours and the on-time delivery rate. Treat dwell time as the time between vehicle arrival at the studio and customer handoff. A delivery is on time when the actual handoff date is on or before the scheduled delivery date. Only include deliveries that were completed and have a non-null actual handoff timestamp.
