Running Total Spend and Conversions | Dataford Interview Questions

Netflix Ads marketing teams need a chronological view of cumulative campaign performance. Write a PostgreSQL query that combines campaign metadata with daily performance records for active Netflix Ads campaigns during February 2025.

Requirements

Aggregate spend and conversions across all qualifying campaigns for each performance date.
Treat NULL spend or conversion values as zero.
Calculate running totals for spend and conversions in date order, returning only dates with recorded performance.

Schema

campaigns

Column	Type	Description
campaign_idPK	INT	Unique campaign identifier
campaign_name	VARCHAR(100)	Netflix Ads campaign name
channel	VARCHAR(50)	Marketing acquisition channel
status	VARCHAR(20)	Current campaign status
audience_segment	VARCHAR(50)	Target audience segment

campaign_daily_performance

Column	Type	Description
performance_idPK	INT	Unique performance record identifier
campaign_id	INT	Related campaign identifier
performance_date	DATE	Date of campaign performance
spend_usd	NUMERIC(12,2)	Advertising spend in US dollars
conversions	INT	Attributed conversion count

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