Dataford
Dataford
Top 50
Topic roadmap
Updated weekly · Last refresh Nov 2

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
~16htotal time
46companies covered
Track your progressSign up free to work through all 50 questions and resume where you left off.
Start practicing free →
1
SQL & Data ManipulationStart here. 45 questions · ~850 min
Analyze Time Series DataMedium
Practice

Summarize valid time series observations by month and identify each series' latest available month.

data preparationDate FunctionsAnalysisLa Banque PostaleTexas Mutual InsurancePhysicsX
End-to-End Take-Home Case StudyHard
Practice

Prepare modeling records, calculate segment-level error metrics, compare model versions, and summarize management assumptions with PostgreSQL.

data preparationcase studydata validationRobinhood
Cleaning Messy DatasetsHard
Practice
Recently asked

Clean, standardize, deduplicate, and validate NHS appointment records before analysis.

analytical skillsdata preparationdata cleaningIIndustry-Leading National Security ConsultancyNHS
Validate Data IntegrityMedium
Practice
Recently asked

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

data preparationdata anomalydata validationKeystonePaytm
Data Clearing and ModelingHard
Practice
Recently asked

Clean raw reality-event data and produce ranked creator engagement summaries.

data relationshipsdata preparationdata cleaningTikTok
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
SQL Joins and DataFrame PrepMedium
Practice
Recently asked

Show how to combine related datasets using SQL joins and return matched and unmatched records.

data preparationJoinsData ManipulationTredence
Regression With R or PythonMedium
Practice
Recently asked

Prepare fund and benchmark return data for regression analysis and calculate alpha, beta, R-squared, and model ranking.

data preparationanalytics toolsRegressionStepStone Group
More SQL & Data Manipulation questions with a free account

Sign up to see every question

Create a free account to unlock this list and practice real interview questions.

Get my prep plan
2
More topics5 questions · ~94 min
More questions with a free account
The finish line: interview-readyComplete all 50 questions to finish this plan.