Public task directory

Technical interview practice tasks

Every entry below is a crawlable link to a unique public task page. This directory complements the interactive filters and keeps the complete catalog connected through standard pagination.

Page 363 of 386 · 18,491 tasks

SQL Case · Easy · 20 min

Travel booking: Return the latest event for each traveler

Travel booking: Return the latest event for each traveler.

View task

SQL Case · Hard · 45 min

Travel booking: Return one row per traveler with completed lifetime value and latest completed event

Travel booking: Return one row per traveler with completed lifetime value and latest completed event.

View task

SQL Case · Easy · 20 min

Travel booking: Combine live and archived completed events without accidental deduplication

Travel booking: Combine live and archived completed events without accidental deduplication.

View task

SQL Case · Medium · 30 min

Travel booking: Compare completed value with the previous active month

Travel booking: Compare completed value with the previous active month.

View task

SQL Case · Medium · 30 min

Travel booking: Calculate the completed-event rate for every itinerary with activity

Travel booking: Calculate the completed-event rate for every itinerary with activity.

View task

SQL Case · Hard · 45 min

Travel booking: Resolve every itinerary to its root itinerary

Travel booking: Resolve every itinerary to its root itinerary.

View task

SQL Case · Medium · 30 min

Travel booking: Count travelers that produced search_started and later produced booking_confirmed

Travel booking: Count travelers that produced searchstarted and later produced bookingconfirmed.

View task

SQL Case · Medium · 30 min

Travel booking: Rank travelers by completed amount inside each region

Travel booking: Rank travelers by completed amount inside each region.

View task

SQL Case · Medium · 30 min

Travel booking: Find booking_confirmed events that happened within seven days of the same traveler's previous success

Travel booking: Find bookingconfirmed events that happened within seven days of the same traveler's previous success.

View task

SQL Case · Hard · 45 min

Travel booking: Calculate the rolling average over each traveler's current and previous two events

Travel booking: Calculate the rolling average over each traveler's current and previous two events.

View task

SQL Case · Medium · 30 min

Travel booking: Measure the share of travelers in each segment that ever reached booking_confirmed

Travel booking: Measure the share of travelers in each segment that ever reached bookingconfirmed.

View task

SQL Case · Medium · 30 min

Travel booking: Split each traveler's events when inactivity exceeds 30 minutes

Travel booking: Split each traveler's events when inactivity exceeds 30 minutes.

View task

SQL Case · Easy · 20 min

Travel booking: Produce one status summary row per traveler

Travel booking: Produce one status summary row per traveler.

View task

SQL Case · Medium · 30 min

Travel booking: Find the itinerary with the largest completed value in each category

Travel booking: Find the itinerary with the largest completed value in each category.

View task

SQL Case · Medium · 30 min

Travel booking: Return the two highest-value travelers in each segment

Travel booking: Return the two highest-value travelers in each segment.

View task

SQL Case · Easy · 20 min

Travel booking: List travelers that never produced a booking_confirmed event

Travel booking: List travelers that never produced a bookingconfirmed event.

View task

SQL Case · Easy · 20 min

Calculate delivered units as a percentage of ordered units by destination region

Calculate delivered units as a percentage of ordered units by destination region.

View task

SQL Case · Hard · 45 min

Produce one stock-health row per warehouse-product pair that has activity

Produce one stock-health row per warehouse-product pair that has activity.

View task

SQL Case · Medium · 30 min

Calculate current inventory value for each warehouse

Calculate current inventory value for each warehouse.

View task

SQL Case · Easy · 20 min

List shipments delivered after their promised timestamp

List shipments delivered after their promised timestamp.

View task

SQL Case · Medium · 30 min

Find movements after which the running on-hand balance became negative

Find movements after which the running on-hand balance became negative.

View task

SQL Case · Easy · 20 min

Calculate current stock for every warehouse and product that has movements

Calculate current stock for every warehouse and product that has movements.

View task

SQL Case · Easy · 20 min

Find warehouse-product pairs whose current stock is at or below the product reorder point

Find warehouse-product pairs whose current stock is at or below the product reorder point.

View task

SQL Case · Hard · 45 min

Summarize delivery reliability from each warehouse to each destination region

Summarize delivery reliability from each warehouse to each destination region.

View task

SQL Case · Medium · 30 min

Calculate the running quantity for every warehouse-product movement

Calculate the running quantity for every warehouse-product movement.

View task

SQL Case · Medium · 30 min

Rank warehouses by average late-delivery hours, treating early deliveries as zero late hours

Rank warehouses by average late-delivery hours, treating early deliveries as zero late hours.

View task

SQL Case · Hard · 45 min

Find each customer’s longest run of failed payments before a success resets the run

Find each customer’s longest run of failed payments before a success resets the run.

View task

SQL Case · Medium · 30 min

Calculate daily succeeded payment volume and its cumulative total

Calculate daily succeeded payment volume and its cumulative total.

View task

SQL Case · Easy · 20 min

Find succeeded payments by the same merchant, customer, and amount within two minutes of the previous match

Find succeeded payments by the same merchant, customer, and amount within two minutes of the previous match.

View task

SQL Case · Easy · 20 min

Calculate fraud-related refund value by merchant

Calculate fraud-related refund value by merchant.

View task

SQL Case · Medium · 30 min

Measure refunded value as a percentage of succeeded payment value

Measure refunded value as a percentage of succeeded payment value.

View task

SQL Case · Hard · 45 min

Build one payment-health row per merchant

Build one payment-health row per merchant.

View task

SQL Case · Easy · 20 min

Subtract refunds from succeeded payment value for each merchant

Subtract refunds from succeeded payment value for each merchant.

View task

SQL Case · Medium · 30 min

Find payments that failed at least once before eventually succeeding

Find payments that failed at least once before eventually succeeding.

View task

SQL Case · Medium · 30 min

Show each region’s share of fraud-refund value

Show each region’s share of fraud-refund value.

View task

SQL Case · Easy · 20 min

Calculate payment success rate for each method

Calculate payment success rate for each method.

View task

SQL Case · Easy · 20 min

Find users who created their first project no more than seven days after signup

Find users who created their first project no more than seven days after signup.

View task

SQL Case · Hard · 45 min

Find every user whose longest run of consecutive login dates is at least two days

Find every user whose longest run of consecutive login dates is at least two days.

View task

SQL Case · Easy · 20 min

Count distinct users with at least one event on each calendar day

Count distinct users with at least one event on each calendar day.

View task

SQL Case · Medium · 30 min

Measure whether each signup-date cohort returned for a login on the next calendar day

Measure whether each signup-date cohort returned for a login on the next calendar day.

View task

SQL Case · Medium · 30 min

Calculate the elapsed hours between each user’s first and last event

Calculate the elapsed hours between each user’s first and last event.

View task

SQL Case · Easy · 20 min

Return the most recent event for every user who has activity

Return the most recent event for every user who has activity.

View task

SQL Case · Easy · 20 min

Measure the share of users in each plan who have ever created a project

Measure the share of users in each plan who have ever created a project.

View task

SQL Case · Medium · 30 min

Count users who viewed pricing and then purchased later, without counting purchases that happened first

Count users who viewed pricing and then purchased later, without counting purchases that happened first.

View task

SQL Case · Hard · 45 min

Attribute purchase value only when it occurred after the user’s first project creation

Attribute purchase value only when it occurred after the user’s first project creation.

View task

SQL Case · Medium · 30 min

Split each user’s events into sessions whenever the inactivity gap exceeds 30 minutes

Split each user’s events into sessions whenever the inactivity gap exceeds 30 minutes.

View task

SQL Case · Easy · 20 min

Count applications attributed to each candidate source

Count applications attributed to each candidate source.

View task

SQL Case · Medium · 30 min

Summarize each interviewer’s positive recommendation rate

Summarize each interviewer’s positive recommendation rate.

View task