Top Sellers From Meeting Graph | Dataford Interview Questions

Deliverr's analytics team wants to identify the strongest collaboration pairs from internal meetings. Write a PostgreSQL query that returns the top three pairs of people who attended completed meetings together during January 2025.

Requirements

Generate each unordered pair only once, never pairing a person with themselves.
Count distinct completed meetings attended by both people, ignoring cancelled, scheduled, out-of-range, and invalid attendee rows.
Return each person's name, the number of shared meetings, the date of their most recent shared meeting, and the pair's rank.
Return exactly three pairs. Break ties deterministically by the first person's name and then the second person's name.
Use multiple CTEs, joins, aggregation, and a window function.

Schema

people

Column	Type	Description
person_idPK	INT	Unique employee identifier
full_name	VARCHAR(100)	Employee display name
team	VARCHAR(80)	Employee team

meetings

Column	Type	Description
meeting_idPK	INT	Unique meeting identifier
organizer_id	INT	Employee who organized the meeting
meeting_date	DATE	Calendar date of the meeting
status	VARCHAR(20)	Meeting lifecycle status

meeting_attendees

Column	Type	Description
meeting_idPK	INT	Referenced meeting identifier
person_idPK	INT	Referenced attendee identifier

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