Rank Fastest-Growing Seller Revenue | Dataford Interview Questions

You are given seller order data from a marketplace. Write a PostgreSQL query that identifies the sellers whose revenue is growing fastest month over month, based on the largest percentage increase in the latest month compared with the previous month. Return one row per seller with their latest month, previous month revenue, growth amount, and growth rate, then rank sellers from highest to lowest growth rate.

Use window functions to compare each seller’s monthly revenue to the prior month. Exclude sellers who do not have revenue in both months needed for the comparison.

Schema

seller_orders

Column	Type	Description
order_idPK	INT	Primary key for each order
seller_id	INT	Unique seller identifier
seller_name	VARCHAR(255)	Seller display name
order_date	DATE	Date the order was completed
order_revenue	DECIMAL(10,2)	Revenue from the order

Your question is Rank Fastest-Growing Seller Revenue. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Use window functions to compare each seller’s monthly revenue to the prior month. Exclude sellers who do not have revenue in both months needed for the comparison.

Schema

seller_orders

Column	Type	Description
order_idPK	INT	Primary key for each order
seller_id	INT	Unique seller identifier
seller_name	VARCHAR(255)	Seller display name
order_date	DATE	Date the order was completed
order_revenue	DECIMAL(10,2)	Revenue from the order

Your question is Rank Fastest-Growing Seller Revenue. Start with the requirements and the one table in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.