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 359 of 386 · 18,491 tasks

SQL Case · Hard · 45 min

Model prediction analytics: Measure whether each creation-date cohort returned on the next calendar day

Model prediction analytics: Measure whether each creation-date cohort returned on the next calendar day.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Keep the latest row for each external event key

Model prediction analytics: Keep the latest row for each external event key.

View task

SQL Case · Easy · 20 min

Model prediction analytics: Find consumers with no activity after the first active month's end

Model prediction analytics: Find consumers with no activity after the first active month's end.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Find completed events above the same consumer's completed-event average

Model prediction analytics: Find completed events above the same consumer's completed-event average.

View task

SQL Case · Easy · 20 min

Model prediction analytics: Return the first prediction_accepted timestamp for each consumer that succeeded

Model prediction analytics: Return the first predictionaccepted timestamp for each consumer that succeeded.

View task

SQL Case · Easy · 20 min

Model prediction analytics: Find events whose model reference does not exist

Model prediction analytics: Find events whose model reference does not exist.

View task

SQL Case · Easy · 20 min

Model prediction analytics: Return the latest event for each consumer

Model prediction analytics: Return the latest event for each consumer.

View task

SQL Case · Hard · 45 min

Model prediction analytics: Return one row per consumer with completed lifetime value and latest completed event

Model prediction analytics: Return one row per consumer with completed lifetime value and latest completed event.

View task

SQL Case · Easy · 20 min

Model prediction analytics: Combine live and archived completed events without accidental deduplication

Model prediction analytics: Combine live and archived completed events without accidental deduplication.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Compare completed value with the previous active month

Model prediction analytics: Compare completed value with the previous active month.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Calculate the completed-event rate for every model with activity

Model prediction analytics: Calculate the completed-event rate for every model with activity.

View task

SQL Case · Hard · 45 min

Model prediction analytics: Resolve every model to its root model

Model prediction analytics: Resolve every model to its root model.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Count consumers that produced prediction_requested and later produced prediction_accepted

Model prediction analytics: Count consumers that produced predictionrequested and later produced predictionaccepted.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Rank consumers by completed amount inside each region

Model prediction analytics: Rank consumers by completed amount inside each region.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Find prediction_accepted events that happened within seven days of the same consumer's previous success

Model prediction analytics: Find predictionaccepted events that happened within seven days of the same consumer's previous success.

View task

SQL Case · Hard · 45 min

Model prediction analytics: Calculate the rolling average over each consumer's current and previous two events

Model prediction analytics: Calculate the rolling average over each consumer's current and previous two events.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Measure the share of consumers in each segment that ever reached prediction_accepted

Model prediction analytics: Measure the share of consumers in each segment that ever reached predictionaccepted.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Split each consumer's events when inactivity exceeds 30 minutes

Model prediction analytics: Split each consumer's events when inactivity exceeds 30 minutes.

View task

SQL Case · Easy · 20 min

Model prediction analytics: Produce one status summary row per consumer

Model prediction analytics: Produce one status summary row per consumer.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Find the model with the largest completed value in each category

Model prediction analytics: Find the model with the largest completed value in each category.

View task

SQL Case · Medium · 30 min

Model prediction analytics: Return the two highest-value consumers in each segment

Model prediction analytics: Return the two highest-value consumers in each segment.

View task

SQL Case · Easy · 20 min

Model prediction analytics: List consumers that never produced a prediction_accepted event

Model prediction analytics: List consumers that never produced a predictionaccepted event.

View task

SQL Case · Hard · 45 min

Mobile engagement: Find completed events whose amount exceeds their device_user segment's completed-event average

Mobile engagement: Find completed events whose amount exceeds their deviceuser segment's completed-event average.

View task

SQL Case · Medium · 30 min

Mobile engagement: Find device_users that reached goal_completed no more than seven days after creation

Mobile engagement: Find deviceusers that reached goalcompleted no more than seven days after creation.

View task

SQL Case · Medium · 30 min

Mobile engagement: Return device_user-feature relationships active ten days after the first relationship began

Mobile engagement: Return deviceuser-feature relationships active ten days after the first relationship began.

View task

SQL Case · Easy · 20 min

Mobile engagement: Find device_users with at least two recorded events

Mobile engagement: Find deviceusers with at least two recorded events.

View task

SQL Case · Hard · 45 min

Mobile engagement: Calculate each feature category's share of all completed value

Mobile engagement: Calculate each feature category's share of all completed value.

View task

SQL Case · Easy · 20 min

Mobile engagement: Calculate completed event value for each device_user segment

Mobile engagement: Calculate completed event value for each deviceuser segment.

View task

SQL Case · Hard · 45 min

Mobile engagement: Group consecutive active dates into islands for each device_user

Mobile engagement: Group consecutive active dates into islands for each deviceuser.

View task

SQL Case · Easy · 20 min

Mobile engagement: Count distinct device_users with activity on each day

Mobile engagement: Count distinct deviceusers with activity on each day.

View task

SQL Case · Medium · 30 min

Mobile engagement: Calculate daily completed value and its running total

Mobile engagement: Calculate daily completed value and its running total.

View task

SQL Case · Hard · 45 min

Mobile engagement: Measure whether each creation-date cohort returned on the next calendar day

Mobile engagement: Measure whether each creation-date cohort returned on the next calendar day.

View task

SQL Case · Medium · 30 min

Mobile engagement: Keep the latest row for each external event key

Mobile engagement: Keep the latest row for each external event key.

View task

SQL Case · Easy · 20 min

Mobile engagement: Find device_users with no activity after the first active month's end

Mobile engagement: Find deviceusers with no activity after the first active month's end.

View task

SQL Case · Medium · 30 min

Mobile engagement: Find completed events above the same device_user's completed-event average

Mobile engagement: Find completed events above the same deviceuser's completed-event average.

View task

SQL Case · Easy · 20 min

Mobile engagement: Return the first goal_completed timestamp for each device_user that succeeded

Mobile engagement: Return the first goalcompleted timestamp for each deviceuser that succeeded.

View task

SQL Case · Easy · 20 min

Mobile engagement: Find events whose feature reference does not exist

Mobile engagement: Find events whose feature reference does not exist.

View task

SQL Case · Easy · 20 min

Mobile engagement: Return the latest event for each device_user

Mobile engagement: Return the latest event for each deviceuser.

View task

SQL Case · Hard · 45 min

Mobile engagement: Return one row per device_user with completed lifetime value and latest completed event

Mobile engagement: Return one row per deviceuser with completed lifetime value and latest completed event.

View task

SQL Case · Easy · 20 min

Mobile engagement: Combine live and archived completed events without accidental deduplication

Mobile engagement: Combine live and archived completed events without accidental deduplication.

View task

SQL Case · Medium · 30 min

Mobile engagement: Compare completed value with the previous active month

Mobile engagement: Compare completed value with the previous active month.

View task

SQL Case · Medium · 30 min

Mobile engagement: Calculate the completed-event rate for every feature with activity

Mobile engagement: Calculate the completed-event rate for every feature with activity.

View task

SQL Case · Hard · 45 min

Mobile engagement: Resolve every feature to its root feature

Mobile engagement: Resolve every feature to its root feature.

View task

SQL Case · Medium · 30 min

Mobile engagement: Count device_users that produced feature_opened and later produced goal_completed

Mobile engagement: Count deviceusers that produced featureopened and later produced goalcompleted.

View task

SQL Case · Medium · 30 min

Mobile engagement: Rank device_users by completed amount inside each region

Mobile engagement: Rank deviceusers by completed amount inside each region.

View task

SQL Case · Medium · 30 min

Mobile engagement: Find goal_completed events that happened within seven days of the same device_user's previous success

Mobile engagement: Find goalcompleted events that happened within seven days of the same deviceuser's previous success.

View task

SQL Case · Hard · 45 min

Mobile engagement: Calculate the rolling average over each device_user's current and previous two events

Mobile engagement: Calculate the rolling average over each deviceuser's current and previous two events.

View task

SQL Case · Medium · 30 min

Mobile engagement: Measure the share of device_users in each segment that ever reached goal_completed

Mobile engagement: Measure the share of deviceusers in each segment that ever reached goalcompleted.

View task