Top 24
Prep plan
Updated weekly · Last refresh Aug 30

One call Data Analyst Interview Questions

The questions to prepare for a One call Data Analyst interview. Questions from real interview reports rank first. Updated weekly.

24questions
~3htotal time
Track your progressSign up free to work through all 24 questions and resume where you left off.
Start practicing free →
1
SQL & Data ManipulationStart here. 13 questions + 3 drills · ~134 min
Ensuring SQL Data AccuracyEasy

Explain how to ensure data accuracy in SQL workflows using validation checks, reconciliation, and careful query design.

JoinsData WranglingQualityOne call
Handle Incomplete or Inconsistent DataEasy

Explain how to assess and clean incomplete or inconsistent data before analysis.

Data WranglingCase WhenQualityOne call
Optimizing Slow PostgreSQL Research QueriesMedium

Explain how you diagnosed and optimized a slow PostgreSQL query using execution plans, indexing, and query rewrites.

JoinsData WranglingAggregationsOne call
Explain SQL Join TypesEasy

Explain INNER, LEFT, RIGHT, FULL OUTER, CROSS, and SELF JOINs with examples and when to use each.

JoinsData WranglingGroup ByOne call
Handling Missing and Dirty SQL DataMedium

Explain how to profile, clean, and standardize missing or dirty data before analysis.

Data WranglingCase WhenQualityOne call
Top Customers by Revenue QueryMedium

Tests your SQL skills for ranking and aggregating business metrics.

sql queriesAggregationsOne call
Autonomous vs Manual Drive TimeHard
Practice
Practice drill

Compute per-vehicle daily autonomous vs manual seconds from state-change logs using LEAD and conditional aggregation.

JoinsData WranglingGroup By
Top Customers by Net SalesMedium
Practice
Practice drill

Compute top 10 customers by net sales using joins and aggregations, ordering by revenue with deterministic tie-breaking.

SubqueriesJoinsData WranglingGain DigitalTCSZest AI
Find Spending Variance Drivers by DepartmentHard
Practice
Practice drill

Use joins and LAG to isolate departments driving a large month-over-month spending variance.

JoinsData WranglingGroup ByState of CaliforniaUniversity of ChicagoThe Church of Jesus Christ of Latter-day Saints
More SQL & Data Manipulation questions with a free account
2
Behavioral & Leadership10 questions · ~80 min
Handling Critical Feedback on AnalysisEasy

Tests how you receive and act on feedback about your analysis, including communication, stakeholder management, and self-awareness.

CommunicationOwnershipDealing With AmbiguityOne call
More Behavioral & Leadership questions with a free account
3
More topics1 question · ~8 min
The finish line: interview-readyComplete all 24 questions plus 3 hands-on drills to finish this plan.