Machine Learning Interview Questions

Showing 91–120 of 348 results

• DDeshawHard·Software Engineer
  Explain and Compare SGD and Adam

  Explain how stochastic gradient descent updates model parameters and how Adam modifies those updates using moving estimates of first and second gradient moments. Cover data and labels, leakage-safe features, baselines and model choice, offline evaluation, deployment constraints, monitoring, and drift.

  Machine LearningTechnical Screen
• DisneyMedium·Machine Learning Engineer
  Build Naive Bayes spam classifier with F1

  This question evaluates understanding of probabilistic text classification with Naive Bayes, text preprocessing and feature extraction, and use of the F1 score for performance measurement in a binary spam detection task.

  Machine LearningTechnical Screen
• DropboxMedium·Data Scientist
  Design enterprise file recommendations under ACLs

  This problem tests the ability to design a multi-tenant recommendation system that enforces complex security constraints while maintaining low latency.

  Machine LearningTechnical ScreenRecommendation SystemsMulti-tenancySecurity
• EliseAIMedium·Data Scientist
  Lease Renewal Prediction and Non-Renewal Reason Categorization Take-Home

  A machine learning take-home on predicting lease renewals from tenant conversations and SQLite tables of residents, maintenance work orders and renewal offers. It covers preprocessing, a metric compared with a random baseline, a test-set prediction file, categorizing non-renewal reasons with gte-base embeddings, and presenting the results.

  Machine LearningTechnical Screen
• EEvenUpMedium·Data Scientist
  Build a model to predict wine quality

  This question evaluates predictive modeling and data-science competencies—exploratory data analysis, feature assessment, problem framing (regression vs classification vs ordinal), model selection and validation, evaluation metric choice, and post-model feature-importance interpretation—in the Machine Learning domain, combining conceptual understanding with practical application. It is commonly asked in technical interviews for Data Scientist roles because it tests end-to-end modeling judgment, reasoning about data distributions and variable usefulness, selection of validation and evaluation strategies, and awareness of pitfalls such as collinearity and data leakage.

  Machine LearningTechnical Screen
• EExaHard·Machine Learning Engineer
  Debug a PyTorch Contrastive Loss

  Repair a PyTorch contrastive loss whose matrix multiplication contracts incompatible dimensions instead of producing pairwise scores. Validate aligned rank-two tensors and temperature, create the correct batch-by-batch logits, preserve gradients, and handle low-precision numerical stability.

  Machine LearningTechnical Screen
• ExperianMedium·Data Scientist
  Explain PCA and L2 Normalization in Machine Learning

  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 PCA and L2 Normalization in Machine Learning states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

  Machine LearningTechnical Screen
• FigmaMedium·Machine Learning Engineer
  Clarify a BERT Keyphrase Span-Extraction Task

  Implement and clarify the post-processing decoder for a BERT-based span-extraction model that maps token-level start and end logits back to non-overlapping character-level keyphrases.

  Machine LearningTechnical Screennlpbertspan-extraction
• FHFlatiron HealthMedium·Data Scientist
  Build a robust ML pipeline

  This question evaluates a candidate's competency in designing robust end-to-end ML pipelines, covering temporal data slicing, leakage controls, time-series cross-validation, feature store consistency, offline and business metrics, drift detection and monitoring, online rollout strategies, retraining triggers, and fairness assessment.

  Machine LearningTechnical Screen
• GoogleMedium·Data Scientist
  Build Classifier: Evaluate with AUROC for Imbalanced Data

  Evaluates classifier design for detecting dead links in imbalanced URL data with leakage-safe validation. Strong answers cover leakage-safe features, grouped validation, AUROC versus accuracy, PR metrics, thresholding, deployment, and monitoring.

  Machine LearningTechnical Screen
• GoogleMedium·Data Scientist
  Build Model to Predict Customer Contract Renewal

  Evaluates renewal prediction modeling for enterprise Google Meet contracts. Strong answers define leakage-safe timelines, engineer usage, reliability, support, contract, and customer-health features, compare logistic regression with complex models, and evaluate calibration, lift, and business intervention value.

  Machine LearningTechnical Screen
• GoogleMedium·Data Scientist
  Build and evaluate bad-link classifier

  This question evaluates proficiency in applied machine learning classification, including feature design, training a logistic regression, handling severe class imbalance, selecting evaluation metrics and calibration, choosing thresholds under asymmetric costs, and planning offline-to-online validation and monitoring.

  Machine LearningTechnical Screen
• GoogleHard·Data Scientist
  Build and evaluate illegal-video classifier

  This question tests the ability to architect an end-to-end classification pipeline for high-stakes, multimodal content moderation while accounting for class imbalance, adversarial evasion, and operational safety.

  Machine LearningTechnical ScreenMultimodal MLAdversarial MLSystem Design
• GoogleHard·Machine Learning Engineer
  Compare Language-Model Post-Training Methods

  This question tests your conceptual depth in LLM alignment by asking you to differentiate between supervised fine-tuning (SFT), reinforcement learning from human feedback (RLHF), direct preference optimization (DPO), and group-relative optimization (e.g., GRPO) based on their mathematical objectives and operational characteristics.

  Machine LearningTechnical ScreenLLMAlignmentRLHF
• GoogleHard·Machine Learning Engineer
  Detect and Prevent Reward Hacking

  Assess the candidate's understanding of reward hacking (specification gaming) in reinforcement learning from human feedback (RLHF), focusing on diagnosing exploitation patterns, designing detection metrics, applying conservative policy updates, and implementing recovery safeguards.

  Machine LearningTechnical ScreenRLHFReward ModelingLLM Alignment
• GoogleHard·Data Scientist
  Diagnose and fix flawed model fit

  This question tests your ability to diagnose poor model performance in a binary classification task involving imbalanced data, high-cardinality categorical features, and potential bias.

  Machine LearningTechnical ScreenClassificationImbalanced DataFeature Engineering
• GoogleMedium·Machine Learning Engineer
  Explain GRPO-style training for diffusion models

  This question tests your conceptual understanding of applying Group Relative Policy Optimization (GRPO) to diffusion models, focusing on how reinforcement learning can be used to steer image generation toward specific objective functions without explicit gradient feedback from the decoder.

  Machine LearningTechnical ScreenDiffusion ModelsReinforcement LearningGRPO
• GoogleHard·Machine Learning Engineer
  Explain Importance Sampling in LLM Training

  Tests understanding of importance sampling in modern LLM fine-tuning, focusing on sequence-level likelihood ratios, exponential variance growth, support conditions, and practical mitigations like clipping and diagnostics.

  Machine LearningTechnical Screenreinforcement-learningllm-trainingimportance-sampling
• GoogleHard·Machine Learning Engineer
  Explain KL Divergence in Language Models

  Review KL divergence from its probability definition through directionality, support mismatch, sample estimates, and LLM regularization.

  Machine LearningTechnical Screen
• GoogleMedium·Software Engineer
  Explain LLM fine-tuning and generative models

  This question tests your conceptual understanding of generative model architectures and the practical trade-offs involved in adapting large-scale language models to specific tasks.

  Machine LearningTechnical ScreenLLMFine-tuningGenerative Models
• GoogleMedium·Machine Learning Engineer
  Explain LLM lifecycle and trade-offs

  This question evaluates a candidate's understanding of the end-to-end lifecycle of large language models, covering training data collection and filtering, pretraining objectives, transformer architecture, post-training methods like supervised fine-tuning and preference optimization, and common model or training variants.

  Machine LearningTechnical Screen
• GoogleHard·Machine Learning Engineer
  Explain VAEs, ELBO, KL, and Reparameterization

  Derive and explain the theoretical foundations of Variational Autoencoders (VAEs), linking the Evidence Lower Bound (ELBO) to network architecture, gradient estimation via the reparameterization trick, and posterior collapse.

  Machine LearningTechnical ScreenVariational AutoencodersGenerative ModelsDeep Learning
• GoogleMedium·Data Scientist
  Explain linear regression to non‑technical stakeholders

  This question assesses the ability to communicate complex statistical models to non-technical stakeholders, focusing on clarity, intuition, and identifying limitations.

  Machine LearningTechnical ScreenCommunicationLinear RegressionStatistics
• GoogleMedium·Machine Learning Engineer
  Explain modeling challenges and fixes

  This question evaluates end-to-end ML ownership and operational troubleshooting skills, including detection of data and modeling issues, trade-off analysis, and evidence-based impact measurement within the Machine Learning/MLOps domain.

  Machine LearningTechnical Screen
• GoogleMedium·Machine Learning Engineer
  Explain ranking cold-start strategies

  This question tests your ability to design strategies for surfacing new items and serving new users in a large-scale recommendation system while maintaining relevance and diversity.

  Machine LearningTechnical ScreenRecommender SystemsCold StartEmbeddings
• GoogleHard·Machine Learning Engineer
  Explain transformer architecture and variants

  This question evaluates a candidate's mastery of transformer architecture and related competencies such as attention mechanisms, positional encodings, encoder/decoder variants, computational complexity and scaling, stability and initialization practices, and adaptation of sequence models to molecular representations.

  Machine LearningTechnical Screen
• GoogleMedium·Software Engineer
  How Would You Verify a Smiling-Face Detection Feature in Google Photos?

  A role-related question for software engineers: if your feature detects smiling faces in Google Photos, how would you verify that the detection is correct? It tests defining ground truth, choosing evaluation metrics and thresholds, covering hard cases and demographic slices, and validating the feature before and after launch.

  Machine LearningTechnical Screen
• GoogleMedium·Data Scientist
  Identify and Fix Predictive Model Performance Gaps

  Evaluates predictive-model audit skills across month encoding, feature scaling, and imbalanced classification. Strong answers fix cyclical seasonality, standardize where needed, and adjust losses or thresholds for recall.

  Machine LearningTechnical Screen
• GoogleHard·Machine Learning Engineer
  Interpret Language-Model Perplexity

  Learn the exact likelihood basis of perplexity, correct evaluation details, tokenizer caveats, and limits as an LLM quality metric.

  Machine LearningTechnical Screen
• GoogleHard·Machine Learning Engineer
  List regularization methods and trade-offs

  This question evaluates competency in machine learning regularization and model generalization, covering familiarity with methods such as L1/L2, dropout, early stopping, data augmentation, label smoothing, mixup, normalization, Bayesian priors, and ensembling.

  Machine LearningTechnical Screen