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Top 50 data preparation Interview Questions

The most frequently asked data preparation questions across all roles and companies, ranked by real interview frequency. Updated daily.

50questions
~8htotal time
112companies covered
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1
SQL & Data ManipulationStart here. 34 questions · ~313 min
SQL and Data Manipulation AssessmentMedium
Practice
Recently asked

Prepare a latest-attempt modeling dataset with joined assessment features, missing-value counts, and outcome labels.

data preparationData ManipulationMachine LearningThe Boston Consulting Group
Validate Data IntegrityMedium
Practice

Audit transaction records for missing references, invalid values, duplicate user emails, and unusable dates before analysis.

data preparationdata anomalydata validationKeystonePaytm
Connecting Data Sources in Power BIMedium
Practice

Audit source rows for nulls, invalid values, duplicate references, and missing relationships before Power BI import.

data preparationanalytics toolsdata validationDeloitte
Clean Incomplete Salesforce Lead RecordsMedium
Practice

Clean Salesforce lead data with CTEs, LEFT JOINs, CASE, and COALESCE to standardize missing values for analysis.

missing valuesdata preparationdata cleaningSalesforce
Spark SQL with PandasMedium
Practice

Prepare an aggregated Spark SQL result for conversion into a Pandas DataFrame while preserving unmatched entities and null values.

data preparationanalytics toolsData Manipulation
Data Cleaning and PreparationMedium
Recently asked

Tests practical data preprocessing skills and judgment about transformations.

data preparationdata cleaningAnalysisHaysBloomberg Industry GroupWWE
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2
Machine Learning10 questions · ~92 min
Feature Engineering MethodsMedium

Tests your practical feature engineering approach and ability to improve model performance.

data preparationFeature EngineeringVisa
Feature Engineering in Machine LearningMedium
Recently asked

Tests your ability to create predictive features and avoid leakage while improving performance.

data preparationFeature EngineeringJ.P. MorganHHitachi VantaraInovex
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3
Pipelines5 questions · ~46 min
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4
More topics1 question · ~9 min
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