Top 34
Prep plan
Updated weekly · Last refresh Oct 17

Extend Data Scientist Interview Questions

The questions to prepare for a Extend Data Scientist interview. Questions from real interview reports rank first. Updated daily.

34questions
~5htotal time
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1
A/B Testing & ExperimentationStart here. 3 questions · ~26 min
2
SQL & Data Manipulation3 questions + 2 drills · ~46 min
3
Statistics & Probability3 questions · ~26 min
Mean and Standard Deviation BasicsEasy

Compute the mean and standard deviation of a dataset, and distinguish the sample standard deviation from the population version.

DistributionsVarianceExpected ValueExtend
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4
Product Sense3 questions · ~26 min
Improve Subscription Customer RetentionMedium

Framework for diagnosing churn and prioritizing product changes to improve retention in a subscription service.

User NeedsUse CasesProduct VisionExtend
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5
Metrics4 questions · ~34 min
Diagnose KPI Drop After ReleaseMedium

Diagnose a post-release KPI drop by separating instrumentation issues from real behavior changes and tracing the problem through the metric hierarchy.

KPILeading IndicatorsDiagnosisExtend
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6
Machine Learning6 questions · ~52 min
Handling Missing Values in MLEasy

Explain practical strategies for handling missing values in a supervised learning workflow, from diagnosis to modeling and validation.

Cross-ValidationFeature EngineeringRegularizationExtend
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7
More topics12 questions · ~103 min
Fraud Detection Batch vs StreamingMedium

Design a fraud pipeline that compares batch, streaming, and hybrid architectures for 120K tx/sec with sub-300 ms decisions and reconciled hourly tables.

Stream ProcessingETLBatch ProcessingExtend
Choosing Classification Evaluation MetricsEasy

Explain which classification metrics to use and how metric choice depends on the business objective and error tradeoffs.

PrecisionAccuracyRecallExtend
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The finish line: interview-readyComplete all 34 questions plus 2 hands-on drills to finish this plan.