January Rider Retention Rate | Dataford Interview Questions

Your question is January Rider Retention Rate. Start with the requirements and the two tables on the right.

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

Problem

Uber wants to measure early rider retention for users who signed up in January 2024. Write a SQL query to calculate the retention rate for that signup cohort.

Define a retained rider as a rider who signed up in January 2024 and completed at least one trip in February 2024.

Requirements

Identify all riders whose signup_date falls between 2024-01-01 and 2024-01-31.
Count how many riders are in that January 2024 signup cohort.
Count how many of those riders completed at least one trip in February 2024.
Return the cohort month, cohort size, retained riders, and retention rate as a percentage rounded to 2 decimals.

Schema

riders

Column	Type	Description
rider_idPK	INT	Unique rider identifier
rider_name	VARCHAR(100)	Rider full name
signup_date	DATE	Date the rider signed up for Uber
city	VARCHAR(50)	Primary signup city

trips

Column	Type	Description
trip_idPK	INT	Unique trip identifier
rider_id	INT	Rider who requested the trip
trip_date	DATE	Date of the trip
trip_status	VARCHAR(20)	Trip outcome such as completed or canceled
fare_usd	NUMERIC(8,2)	Final trip fare in USD