Top 12
Prep plan
Updated weekly · Last refresh Aug 30

Telefónica Data Scientist Interview Questions

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

12questions
~2htotal time
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1
Machine LearningStart here. 3 questions · ~24 min
Imbalanced Fraud Target HandlingMedium

Tests your approach to class imbalance in fraud or anomaly detection models.

Cross-ValidationBias-Variance TradeoffSupervised LearningTelefónica
L1 vs L2 RegularizationEasy

Tests understanding of regularization effects and model selection for churn prediction.

Feature EngineeringRegularizationSupervised LearningTelefónica
Gradient Boosting IntuitionHard

Tests your ability to explain core mechanics of gradient boosting and loss optimization.

Ensemble MethodsDecision TreesGradient DescentTelefónica
2
Behavioral & Leadership4 questions · ~32 min
More Behavioral & Leadership questions with a free account
3
More topics5 questions · ~40 min
Spark Skew OptimizationHard

Tests your performance tuning skills for distributed data processing.

InfrastructureStream ProcessingBatch ProcessingTelefónica
Prioritizing Data to Reduce Repair TimeMedium

Tests your ability to connect data sourcing to operational impact in telecom reliability.

User NeedsValue PropositionPain PointsTelefónica
SQL Top Usage by RegionMedium

Tests SQL windowing and percentile-style logic for telecom usage analytics.

Window FunctionsDate FunctionsRankingTelefónica
Fraud Detection System DesignHard

Evaluates your approach to designing an end-to-end fraud detection system.

system designfraud detectionTelefónica
Recommendation System for Movistar+Hard

Tests product-focused modeling choices for personalization in a large-scale media platform.

User NeedsUse CasesProduct VisionTelefónica

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Hands-on SQL practiceWrite and run real queries in the editor. 3 drills · ~30 min
The finish line: interview-readyComplete all 12 questions plus 3 hands-on drills to finish this plan.