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Machine Learning Interview Questions

Practice 9403 coding, system design and machine learning questions from 546 companies, sorted by role, topic and interview round. Every question has step-by-step hints, a code runner that supports 8 languages and an AI mentor; members also get the full solution walkthrough.

9403
Questions
546
Companies
11
Topics
8
Languages

Showing 1–30 of 46 results

  • AnthropicHardMachine Learning Engineer
    Debug a NumPy Extremely Randomized Trees Classifier

    Anthropic Fellows debugging-OA practice: find the eight crash and accuracy bugs in a from-scratch NumPy Extra-Trees classifier until it matches scikit-learn.

    Machine LearningOnline AssessmentAnthropic FellowsAI Safety Fellowshipdebugging
  • AtlassianMediumData Scientist
    Minimize max L1 radius with k centers in 1D

    This question evaluates algorithmic problem-solving skills and understanding of clustering and optimization concepts, specifically the 1D k-center (minimax L1) problem, greedy feasibility tests, binary-search-on-answer techniques, numerical stability with large coordinates, and time/space complexity analysis relevant for a Data Scientist role.

    Machine LearningOnline Assessment
  • Boston Consulting GroupMediumData Scientist
    Achieve 0.95 precision via thresholding

    This question evaluates probabilistic classifier calibration, threshold selection to achieve a target precision, handling severe class imbalance, and precision–recall based evaluation metrics.

    Machine LearningOnline Assessment
  • Boston Consulting GroupMediumData Scientist
    Build a leak-free sklearn pipeline

    This problem tests the ability to build a robust scikit-learn pipeline that prevents data leakage during preprocessing and hyperparameter tuning while handling class imbalance.

    Machine LearningOnline Assessmentscikit-learndata-leakagepipelines
  • Boston Consulting GroupMediumData Scientist
    Build and evaluate imbalanced binary classifier

    This question evaluates a data scientist's skills in building reproducible machine learning pipelines for imbalanced binary classification, covering temporal splitting to avoid leakage, class imbalance handling, feature preprocessing, probability calibration, threshold selection, and monitoring for calibration drift.

    Machine LearningOnline Assessment
  • Boston Consulting GroupHardData Scientist
    Detect Data Leakage in Supervised Learning Pipelines

    This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Detect Data Leakage in Supervised Learning Pipelines states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Machine LearningOnline Assessment
  • Boston Consulting GroupMediumData Scientist
    Improve Model Generalization with Cross-Validation and Feature Engineering

    This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Improve Model Generalization with Cross-Validation and Feature Engineering states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Machine LearningOnline Assessment
  • Boston Consulting GroupEasyData Scientist
    Scale and Normalize: When to Use Each Method?

    This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Scale and Normalize: When to Use Each Method? states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Machine LearningOnline Assessment
  • Boston Consulting GroupEasyData Scientist
    Train GradientBoostingClassifier with 5-Fold Cross-Validation

    This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Train GradientBoostingClassifier with 5-Fold Cross-Validation states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Machine LearningOnline Assessment
  • C3 AIMediumData Scientist
    Choose a Parameter to Reduce Underfitting in Gradient-Boosted Trees

    Explain why decreasing minimum observations per leaf can reduce gradient-boosted tree underfitting and how to validate the change.

    Machine LearningOnline Assessment
  • C3 AIMediumData Scientist
    Compare How Models Respond to Multicollinearity

    Compare multicollinearity effects in regression, Lasso, logistic regression, decision trees, and boosted trees without overstating immunity.

    Machine LearningOnline Assessment
  • C3 AIMediumSoftware Engineer
    Evaluate Factual Accuracy and Consistency in a Domain-Specific RAG Chatbot

    Evaluate a rare-disease RAG chatbot using domain consistency and expert review, and distinguish factual accuracy from retrieval metrics and lexical overlap.

    Machine LearningOnline Assessment
  • C3 AIMediumData Scientist
    Explain the Margin View of Boosting Classification

    Understand boosting classification through sequential learners, signed margins, surrogate losses, and the limits of training-margin claims.

    Machine LearningOnline Assessment
  • C3 AIMediumData Scientist
    Identify What Does Not Fix Vanishing Gradients

    Explain why raising the learning rate does not fix vanishing gradients and compare skip connections, ReLU, and batch normalization.

    Machine LearningOnline Assessment
  • CVS HealthMediumData Scientist
    Build a leak-free sklearn churn pipeline

    This question evaluates practical competencies in building a reproducible scikit-learn churn prediction pipeline—covering temporal splitting to avoid leakage, preprocessing, calibration, hyperparameter tuning, evaluation with ROC AUC/PR AUC and F1-based thresholds, and permutation feature importance—and is in the Machine Learning domain.

    Machine LearningOnline Assessment
  • CVS HealthMediumData Scientist
    Implement R² and Compare PCA With/Without Scaling

    This question evaluates a candidate's proficiency with regression evaluation metrics and linear-algebra-based dimensionality reduction, specifically implementing a numerically robust R² scorer and performing PCA with and without feature standardization using NumPy.

    Machine LearningOnline Assessment
  • Capital OneMediumData Scientist
    Resolve a Mismatch Between Regression and Classification Metrics

    Tests your ability to diagnose modeling and metric mismatches in credit risk and fraud scenarios, design proper two-stage architectures, and select evaluation metrics aligned with business decisions.

    Machine LearningOnline Assessmentmachine-learningmodel-evaluationregression
  • CoinbaseHardMachine Learning Engineer
    Explain precision/recall and compute NN output

    This question tests the ability to calculate classification performance metrics, explain ensemble model dynamics, and perform manual forward propagation through a small neural network architecture.

    Machine LearningOnline AssessmentClassificationNeural NetworksEnsemble Methods
  • DRWMediumMachine Learning Engineer
    Explain core ML and DL fundamentals

    Explain core ML and DL fundamentals evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Machine LearningOnline Assessment
  • DatabricksMediumData Scientist
    Explain Linear Regression Feature Transformation Equivalence

    This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Explain Linear Regression Feature Transformation Equivalence states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Machine LearningOnline Assessment
  • Goldman SachsHardMachine Learning Engineer
    Evaluate TPR/FPR, sigmoid, and activations

    This question evaluates competency in binary classification metrics (confusion matrices, TPR/FPR), basic neural network forward computation (sigmoid neuron z and output), and knowledge of activation function selection and pitfalls.

    Machine LearningOnline Assessment
  • HBOHardData Scientist
    Define scalable train/validation for churn

    This question assesses the ability to design an end-to-end churn prediction pipeline, focusing on temporal integrity, handling class imbalance, and ensuring robust production deployment.

    Machine LearningOnline AssessmentChurnSystem DesignData Leakage
  • HackerRankMediumMachine Learning Engineer
    Build A Purchase-Intent Prediction Notebook

    Prepare for a machine learning take-home notebook that predicts purchase intent from session features and submits binary outcomes. The prompt focuses on data cleaning, missing values, categorical encoding, model pipelines, weighted F1, threshold tuning, and robust submissions.

    Machine LearningOnline Assessment
  • HeadlandsMediumData Scientist
    What Cross-Validation Reduces: Bias, Variance, Type I or Type II Error

    This question tests your conceptual understanding of how k-fold cross-validation affects the generalization error and how the choice of 'k' influences the trade-off between bias and variance in model performance estimation.

    Machine LearningOnline AssessmentModel EvaluationCross-ValidationStatistics
  • Jane StreetMediumQuantitative Trader
    Analyze trading RFQ competitiveness data

    This question tests your ability to model order flow competitiveness by deriving features from trade logs and assessing the relationship between pricing aggressiveness and win probability.

    Machine LearningOnline AssessmentLogistic RegressionFeature EngineeringMarket Microstructure
  • Morgan StanleyMediumData Scientist
    Answer basic probability and statistics questions

    This problem tests your conceptual understanding of probability distributions, statistical bias in data collection, and the relationship between covariance and linear correlation.

    Machine LearningOnline AssessmentStatisticsProbabilityBias
  • NetflixEasyMachine Learning Engineer
    ML Basics Check: Bayes' Rule, Forward-Pass Arithmetic, KNN and Transformer Concepts

    A set of basic machine learning checks: a Bayes' rule posterior with a low base rate, forward-pass and parameter-count arithmetic for small neural networks, and true-or-false concept checks on k-nearest neighbors and Transformer attention. It tests quick, accurate reasoning on core ML fundamentals.

    Machine LearningOnline Assessment
  • OptiverHardData Scientist
    How to rank statements by likelihood

    This problem tests your ability to translate statistical distributions and categorical data into ranked probabilistic likelihoods, accounting for uncertainty and sample size variance.

    Machine LearningOnline AssessmentProbabilityStatisticsBayesian Inference
  • PinterestHardMachine Learning Engineer
    Answer core ML fundamentals questions

    This question evaluates a candidate's mastery of core Machine Learning fundamentals, including classification metrics (precision and recall) with confusion-matrix interpretation, gradient concepts for optimization, ensemble learning tradeoffs, and the mechanics of a neural network forward pass.

    Machine LearningOnline Assessment
  • PinterestHardMachine Learning Engineer
    Implement Naive Bayes classifier from scratch

    This question evaluates understanding of probabilistic classification, specifically competence in estimating class priors, feature likelihood parameters, and computing posterior scores for Naive Bayes variants.

    Machine LearningOnline Assessment