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Machine Learning Engineer 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 151–180 of 782 results

  • DandyMediumMachine Learning Engineer
    Why do transformers struggle with long context?

    This question evaluates understanding of transformer architectures, attention mechanisms, and scalability trade-offs, assessing competencies in computational complexity, memory usage, and system-level performance implications.

    Machine LearningHR Screen
  • DatabricksMediumMachine Learning Engineer
    Delete a Character From Cover

    This problem tests your ability to manage dynamic string indices by maintaining a set of active intervals and adjusting them efficiently after a character deletion.

    Coding & AlgorithmsOnsiteStringsIntervalsArrays
  • DatabricksMediumMachine Learning Engineer
    Design Harmful Content Detection

    This problem tests the ability to design an end-to-end machine learning system for multimodal harmful content detection at scale, focusing on pipeline architecture, latency, and data governance.

    ML System DesignOnsiteSystem DesignMultimodalScalability
  • DatabricksMediumMachine Learning Engineer
    Design Harmful Content and OOM Detection

    This question tests the ability to design an end-to-end ML system for real-time safety, covering taxonomy, data strategies, model architecture, and operational monitoring.

    ML System DesignOnsiteSystem DesignMLOpsSafety
  • DatabricksMediumMachine Learning Engineer
    Design In-Memory QPS Counter

    This question evaluates the ability to design and implement an in-memory time-series counter and sliding-window aggregation, emphasizing efficient data structures, handling high-frequency events, and memory-time trade-offs.

    Coding & AlgorithmsTechnical Screen
  • DatabricksMediumMachine Learning Engineer
    Detect Harmful Content in LLM Prompts and Responses

    Design a machine learning system that detects harmful content in prompts sent to, and responses produced by, a large language model. Tests policy-driven framing, labeling and adversarial data, layered classifiers under latency limits, per-category evaluation, streaming checks and monitoring.

    ML System DesignOnsite
  • DatabricksMediumMachine Learning Engineer
    Implement Gradient Descent Regression

    This problem tests your understanding of linear regression by requiring the implementation of a gradient descent optimizer from scratch to minimize the Mean Squared Error loss.

    Machine LearningOnsiteLinear RegressionGradient DescentOptimization
  • DatabricksMediumMachine Learning Engineer
    Implement Linear Regression Gradient Descent

    This question tests the ability to implement batch gradient descent for simple linear regression from scratch, requiring the derivation of gradients for weights and bias, and understanding how to optimize convergence.

    Machine LearningOnsiteGradient DescentLinear RegressionOptimization
  • DatabricksMediumMachine Learning Engineer
    Implement Simple Linear Regression with Gradient Descent from Scratch

    Write simple linear regression trained with gradient descent from scratch, choosing the loss, learning rate and stopping rule yourself. Tests deriving the gradients correctly, writing a runnable training loop, understanding feature scaling and convergence, and verifying results against a closed-form fit.

    Machine LearningOnsite
  • DatabricksMediumMachine Learning Engineer
    Retrieve and Rerank Tables and Notebooks for a Data-Aware Coding Agent

    Design the retrieval system that lets an internal coding agent find the right tables and notebooks to answer data questions. Tests what to index for each asset type, hybrid retrieval plus reranking, handling noisy or stale assets, access control, and metric design from retrieval to final answers.

    ML System DesignOnsite
  • DatadogHardMachine Learning Engineer
    Implement Focal Loss for Class-Imbalanced Classification

    Tests the ability to implement binary focal loss with raw logits from first principles, emphasizing numerical stability, custom weighting, and tensor reduction strategies.

    Machine LearningTechnical Screenmachine-learningdeep-learningpytorch
  • DatadogHardMachine Learning Engineer
    Implement Grouped-Query Attention (GQA)

    Implement the Grouped-Query Attention (GQA) mechanism commonly used in modern LLMs to balance serving memory bandwidth with generation quality. You will handle tensor reshaping/expansion across query head groups, scaled dot-product attention, and causal masking.

    Machine LearningTechnical Screendeep-learningtransformerspytorch
  • DaveEasyMachine Learning Engineer
    Own and Resolve a Bug in Production

    This question tests your ability to structure a high-stakes professional failure using the STAR method, focusing on technical accountability and systemic improvement.

    Behavioral & LeadershipOnsiteBehavioralLeadershipProduction-Support
  • DaveEasyMachine Learning Engineer
    Parse JSON Accounts into Typed Python Objects and Prepare Features

    This problem tests your ability to sanitize and transform raw JSON account data into a structured format while enforcing strict numerical integrity and data consistency.

    Data Manipulation (SQL/Python)OnsitePythonData CleaningJSON
  • DeshawMediumMachine Learning Engineer
    Implement sqrt and parity-based array rearrangement

    In the Coding & Algorithms domain, this prompt evaluates numerical methods and precision handling for implementing a square-root function without library support, together with in-place array manipulation, partitioning and complexity reasoning for parity-based rearrangement, testing competencies in algorithm design, numerical approximation, and space-efficient data transformations. These problems are commonly asked to assess understanding of numerical stability, error bounds and iterative approximation as well as mastery of in-place ordering/partitioning strategies and time/space complexity analysis, requiring both conceptual understanding of mathematical properties and practical implementation ability.

    Coding & AlgorithmsTechnical Screen
  • DisneyMediumMachine 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
  • DistylMediumMachine Learning Engineer
    Design Streaming Speech and Multi-Model Chat Systems

    A two-part system-design interview covering incremental multi-speaker transcription and a streaming multi-model chat service. Candidates must reason about ordering, revisions, backpressure, model fallback, durable conversation state, safety, and recovery.

    ML System DesignOnsite
  • DoorDashMediumMachine Learning Engineer
    Design a scalable recommendation serving system

    This question evaluates an engineer's ability to design scalable, low-latency, and resilient online recommendation serving infrastructure, emphasizing caching strategies, partitioning/sharding, data storage consistency, and observability.

    System DesignOnsite
  • DoorDashMediumMachine Learning Engineer
    Design personalized restaurant search and recommendations

    This question tests the ability to design an end-to-end personalized restaurant recommendation system, covering feature engineering, retrieval-ranking architecture, and infrastructure trade-offs.

    System DesignTechnical ScreenRecommendation SystemsRankingSearch
  • DoorDashHardMachine Learning Engineer
    Discuss ML infrastructure fundamentals

    Discuss ML infrastructure fundamentals evaluates ML product requirements, data/labeling, modeling, serving architecture, evaluation, monitoring, and trade-offs in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    ML System DesignTechnical Screen
  • DoorDashMediumMachine Learning Engineer
    Find closest value to a target in a BST

    This question evaluates understanding of binary search tree properties and numeric approximation, measuring competence in tree traversal, comparison logic, and algorithmic efficiency under input-size constraints.

    Coding & AlgorithmsOnsite
  • DoorDashMediumMachine Learning Engineer
    How would you prevent wrong items in deliveries?

    This question evaluates systems thinking, root-cause analysis, metrics-driven decision-making, and cross-functional leadership in operational product-process contexts.

    Behavioral & LeadershipOnsite
  • DoorDashMediumMachine Learning Engineer
    Minimize batches and allocate riders by time

    This problem tests your ability to optimize resource scheduling by grouping tasks with overlapping time windows into the minimum number of batches, subject to capacity constraints.

    Coding & AlgorithmsTechnical ScreenGreedyIntervalsBin Packing
  • DoorDashEasyMachine Learning Engineer
    Walk Through an ML Project

    This question assesses the candidate's ability to communicate a full-lifecycle machine learning project, focusing on problem scoping, technical execution, and business impact.

    Behavioral & LeadershipTechnical ScreenML LifecycleProduct ThinkingModel Deployment
  • ExaHardMachine 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
  • ExaHardMachine Learning Engineer
    Design a Streaming Percentile Estimator

    Design a streaming percentile estimator without storing every observation, and define rank error precisely. Compare a deterministic single-stream summary with t-digest-style centroids across memory, update cost, duplicates, skew, tail accuracy, and distributed merge limitations.

    Statistics & MathTechnical Screen
  • FaireMediumMachine Learning Engineer
    Data quality, lineage, monitoring and backfill design for an ML feature store

    A discussion-based ML infrastructure design round on keeping the data behind models reliable and well governed. It covers defining and measuring availability, freshness, completeness, validity, consistency, distribution, compliance and lineage, monitoring a feature store, and planning a safe, correct data backfill.

    ML System DesignOnsite
  • FaireMediumMachine Learning Engineer
    Design a real-time model inference platform: deployment, scaling and monitoring

    An ML system design question asking for a real-time model inference platform that teams use to serve trained models inside their applications' request paths. It tests safe model deployment and rollback, per-model autoscaling and batching, failure handling, and monitoring from infrastructure up to model quality.

    ML System DesignOnsite
  • FigmaMediumMachine 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
  • FigmaMediumMachine Learning Engineer
    Design Feed Ranking and HTML Generation

    This problem tests the design of a dual-purpose ML system: a personalized content feed ranker and an LLM-based component that translates user intent into rendered HTML widgets.

    ML System DesignOnsiteRankingLLMRecommendation Systems