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Known Interview Questions

The questions to prepare for Known interviews, across all roles. Questions from real interview reports rank first. Updated weekly.

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1
SQL & Data ManipulationStart here. 6 questions + 2 drills · ~70 min
Median CTR by Meta CampaignHard
Practice

Use window functions to compute median CTR per Meta ad campaign, excluding rows with zero or null impressions.

Known
Find Duplicate Rows QueryEasy
Practice
Practice drill

Identify duplicate Dover India asset records using GROUP BY and HAVING, excluding the unique record identifier.

Data WranglingsqlAggregationsDover IndiaDataAnnotation
Analyze Decision Impact by RegionEasy
Practice
Practice drill

Use joins, CASE WHEN, and date filtering to compare outcome rates before and after a decision.

Data WranglingDiagnosisAggregationsHarbourVest Partners
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2
Machine Learning8 questions · ~67 min
L1 vs L2 RegularizationMedium

Explain how L1 and L2 regularization differ geometrically and probabilistically, grounded in a practical supervised learning example.

Feature EngineeringRegularizationSupervised LearningKnown
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3
Statistics & Probability8 questions · ~67 min
Testing a Conversion Rate DropMedium

Explain how to test whether an observed 5% conversion rate drop is statistically significant in an experiment or before-after comparison.

Hypothesis TestingData AnalysisStatistical SignificanceKnown
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4
A/B Testing & Experimentation4 questions · ~33 min
Measure Marketing Campaign IncrementalityMedium

Design an incrementality test for a new customer marketing campaign with explicit MDE, guardrails, power, and rollout criteria.

ExperimentationHypothesis TestingGuardrail MetricsKnown
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5
Metrics3 questions · ~25 min
Diagnose a 15% KPI DropMedium

Tests KPI debugging, root-cause analysis, and distinguishing instrumentation from product changes.

KPILeading IndicatorsDiagnosisKnown
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6
Execution4 questions · ~33 min
Backend for Marketing AutomationHard

Tests your backend architecture and reliability planning for Known marketing automation.

high availabilityfault toleranceKnown
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7
More topics17 questions · ~142 min
Define Metrics for New FeaturesMedium

Define a success metric for a new feature that captures real user value, not just raw usage.

MetricsFeature Prioritizationuser valueKnown
Rolling 7-Day Purchase AverageMedium

Tests ability to implement time-window calculations correctly in Pandas.

transformationsData WranglingTime SeriesKnown
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