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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 301–330 of 782 results

  • MercorMediumMachine Learning Engineer
    Design a DAG Pipeline Runner for Data-Labeling Jobs

    Design a multi-tenant service that runs user-defined DAGs of automated steps (pre-processing, model pre-labeling, QA checks, exports), tracks every run, and survives crashes. Tests data modeling, separating the scheduler from workers, durable state, retries and idempotency, tenant fairness and observability.

    System DesignOnsiteworkflow-orchestrationdistributed-systemsstate-machines
  • MercorMediumMachine Learning Engineer
    Design a High-Demand Event Ticket Marketplace

    Design an event ticketing platform capable of handling flash-sale spikes without overselling, featuring transactional seat holds, idempotent payment processing, and virtual queueing.

    System DesignOnsitesystem-designdistributed-systemsconcurrency
  • MercorEasyMachine Learning Engineer
    Design a Social Feed

    Design an end-to-end personalized social feed system capable of serving low-latency ranked content while handling hybrid fanout, multi-stage ML candidate retrieval, and stable pagination.

    System DesignTechnical Screensystem-designfeed-rankingrecommendation-systems
  • MercorMediumMachine Learning Engineer
    Design a workflow orchestration system that runs multi-step jobs reliably

    A system design question asking you to build a workflow system where users define multi-step workflows with dependencies, start runs, and track progress. It tests data modeling, orchestration and worker architecture, durable state, retries and idempotency, fairness between tenants, scaling and observability.

    System DesignOnsite
  • MercorMediumMachine Learning Engineer
    Evaluate Noisy Data for LLM Post-Training

    Design a curation and validation framework to evaluate, filter, and safely integrate a large, noisy dataset into an LLM post-training pipeline without degrading model performance.

    Machine LearningTechnical ScreenLLM Post-TrainingData CurationModel Evaluation
  • MercorMediumMachine Learning Engineer
    Implement a Referral Network

    Design and implement an in-memory referral network as a directed acyclic graph (DAG) supporting cycle-safe edge insertion, depth-bounded reachability queries, and expected reward computation under geometric decay.

    Coding & AlgorithmsOnsiteGraph AlgorithmsDAGBFS
  • MercorMediumMachine Learning Engineer
    Review a Compact GPT-Style Transformer Implementation

    Assess and debug a compact decoder-only Transformer implementation. Candidates trace tensor dimensions through causal multi-head self-attention, identify flaws in next-token loss alignment and KV-cached generation, and establish equivalence between cached and uncached forward passes.

    Machine LearningOnsiteTransformersPyTorchDeep Learning
  • MetaMediumMachine Learning Engineer
    Answer behavioral questions on projects and feedback

    This set of behavioral questions evaluates communication, leadership, adaptability, handling ambiguity, feedback exchange, and project ownership within the context of machine learning engineering projects.

    Behavioral & LeadershipOnsite
  • MetaMediumMachine Learning Engineer
    Answer core behavioral questions using STAR

    This question evaluates behavioral and leadership competencies—including communication, teamwork, conflict resolution, time and scope management, and mentorship—within the context of a Machine Learning Engineer role.

    Behavioral & LeadershipOnsite
  • MetaMediumMachine Learning Engineer
    Answer senior-level behavioral interview questions

    This question evaluates leadership, decision-making, risk management, stakeholder management, and impact-communication skills for a senior Machine Learning Engineer role within the Behavioral & Leadership category.

    Behavioral & LeadershipTechnical Screen
  • MetaHardMachine Learning Engineer
    Architect an asynchronous RL post-training system

    This question evaluates a candidate's ability to design an asynchronous reinforcement-learning post-training system for a production chat LLM, testing competencies in ML system architecture, distributed training and serving separation, streaming data engineering, reward modeling and credit assignment, safety/compliance, and deployment/operations.

    ML System DesignOnsite
  • MetaMediumMachine Learning Engineer
    Build Friend Recommendations

    This problem tests your ability to manipulate graph-like data structures to perform neighbor analysis and efficient set operations to rank potential connections.

    Coding & AlgorithmsTechnical ScreenGraphsHash MapsSocial Network Analysis
  • MetaHardMachine Learning Engineer
    Build a Friend Recommender

    This problem tests your ability to implement a graph-based recommendation algorithm using common neighbors and popularity constraints to rank potential connections.

    Coding & AlgorithmsOnsiteGraphSortingRecommendation System
  • MetaMediumMachine Learning Engineer
    Build harmful-content text classifier

    This problem evaluates your ability to design a robust text classification system for identifying harmful content, emphasizing strategies for data imbalance, labeling ambiguity, and real-time inference.

    Machine LearningOnsiteNLPClassificationMLOps
  • MetaMediumMachine Learning Engineer
    Check diagonal and compute window statistics

    This question evaluates understanding of array and matrix manipulation, sliding-window and streaming statistics, and appropriate data-structure choices for maintaining aggregates and order-statistics such as moving averages and sliding-window medians.

    Coding & AlgorithmsTechnical Screen
  • MetaMediumMachine Learning Engineer
    Check diagonal equality in a matrix

    This question evaluates skill in matrix manipulation and algorithmic reasoning, specifically understanding diagonal traversal, equality checks, and handling boundary conditions such as empty matrices, single-row or single-column inputs, and negative values.

    Coding & AlgorithmsTechnical Screen
  • MetaMediumMachine Learning Engineer
    Compute sliding-window medians

    This question evaluates proficiency in designing and analyzing efficient sliding-window algorithms and data structures for computing running medians, including correct handling of duplicates, deletions, and the convention for defining the median when k is even.

    Coding & AlgorithmsTechnical Screen
  • MetaMediumMachine Learning Engineer
    Compute the next lexicographic permutation

    This problem tests your ability to manipulate array elements in-place to find the next lexicographically ordered sequence, focusing on understanding the properties of permutations.

    Coding & AlgorithmsOnsiteArraysPermutationsTwo Pointers
  • MetaMediumMachine Learning Engineer
    Debug and optimize a card-drawing strategy

    This problem tests your ability to simulate card-drawing probabilities, debug flawed logic in iterative selection strategies, and optimize performance for repeated simulations.

    Coding & AlgorithmsOnsiteAlgorithmsSimulationProbability
  • MetaMediumMachine Learning Engineer
    Deep copy a linked list with random pointers

    This problem tests your ability to manipulate complex pointer structures and maintain object identity across a deep copy operation in a non-linear linked list.

    Coding & AlgorithmsTechnical ScreenLinked ListHash TablePointers
  • MetaHardMachine Learning Engineer
    Demonstrate leadership and ensure data compliance

    This question evaluates leadership, program execution, stakeholder management, risk and tradeoff reasoning in machine learning engineering, along with expertise in data privacy, regulatory compliance, and operational data governance for user-data-driven systems.

    Behavioral & LeadershipOnsite
  • MetaMediumMachine Learning Engineer
    Derive Linear Regression Solution

    This problem tests your ability to derive the Ordinary Least Squares (OLS) closed-form solution for a simple linear regression model and analyze the underlying mathematical assumptions.

    Machine LearningTechnical ScreenLinear RegressionMathematicsMLE
  • MetaMediumMachine Learning Engineer
    Describe handling intense time pressure

    This question evaluates a candidate's ability to perform under intense time pressure and multitask, specifically assessing prioritization, trade-off communication, stakeholder management, stress resilience, and execution skills relevant to machine learning engineering within a Behavioral & Leadership context.

    Behavioral & LeadershipOnsite
  • MetaHardMachine Learning Engineer
    Design Nearby and Notification Ranking

    This question evaluates competency in designing large-scale machine learning systems for real-time recommendations and notification ranking, covering candidate generation, ranking, feature engineering, online serving, latency management, and multi-objective trade-offs; it is commonly asked to assess the ability to translate product objectives into system architecture and measurable evaluation metrics while addressing freshness, cold-start, moving users, and notification fatigue. The domain is ML system design—recommender systems, ranking, and online serving—and the level spans both high-level conceptual architecture and practical application concerns such as serving latency, data freshness, training labels, and evaluation.

    ML System DesignOnsite
  • MetaMediumMachine Learning Engineer
    Design Place Recommendation System

    This question evaluates machine learning system design skills specific to recommender systems, including competencies in feature engineering, candidate generation and ranking, data engineering, online serving, latency and real-time context handling, evaluation metrics, and fairness/bias mitigation.

    ML System DesignOnsite
  • MetaMediumMachine Learning Engineer
    Design a Large-Scale Personalized Recommendation System End to End

    An ML system design question asking you to design a large-scale personalized recommendation system end to end, from candidate retrieval and multi-stage ranking to training data, evaluation, serving and monitoring. It tests problem framing, latency budgeting, cold start, feedback loops and online experimentation.

    ML System DesignOnsite
  • MetaMediumMachine Learning Engineer
    Design a Real-Time Question-Answering Chatbot: Training Data, RL Tasks and Rewards

    An AI design question about a chatbot that answers user questions in real time. It tests the low-latency serving and retrieval path, training data collection for fine-tuning and preference learning, reinforcement-learning task and reward design, and the ability to name reward weaknesses and mitigate them.

    ML System DesignTechnical Screen
  • MetaMediumMachine Learning Engineer
    Design a Short-Video Recommendation System

    This question tests your ability to design a multi-stage recommendation pipeline for a high-traffic short-video platform, focusing on candidate retrieval, ranking models, and system scalability.

    ML System DesignTechnical ScreenRecommendation SystemsScalabilityRanking
  • MetaMediumMachine Learning Engineer
    Design a newsfeed dislike model

    This problem tests the ability to design an end-to-end ML system for predicting user dissatisfaction, focusing on label definition, feature engineering, and the integration of negative signals into a ranking pipeline.

    ML System DesignOnsiteRecommender SystemsRankingImbalanced Learning
  • MetaHardMachine Learning Engineer
    Design a recommendation system

    This question evaluates competence in designing large-scale recommendation systems and ML engineering skills such as candidate generation, feature store design (offline/online and point-in-time correctness), real-time signal ingestion, ranking and re-ranking, online exploration, cold-start strategies, feedback-bias mitigation, experimentation, and operational reliability. It is commonly asked to assess the ability to make architecture-level trade-offs for scalability, latency and throughput targets, multi-objective optimization, data governance and outage fallback behavior; it falls under the System Design and Machine Learning domain and requires practical, architecture-level application with conceptual trade-off reasoning rather than low-level implementation detail.

    System DesignOnsite