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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 1–30 of 30 results

  • AnthropicMediumMachine Learning Engineer
    Explain multithreading vs multiprocessing

    This question tests your conceptual understanding of how process-based and thread-based concurrency models leverage hardware resources and their respective trade-offs in the context of Python and high-performance ML workloads.

    Software Engineering FundamentalsOnsiteConcurrencyPythonOperating Systems
  • AppleHardMachine Learning Engineer
    Walk Through an Agentic PDF Evaluation Codebase

    This question tests your ability to navigate, critique, and extend a modular codebase designed for evaluating agentic PDF processing pipelines, focusing on evaluation metrics and robust system architecture.

    Software Engineering FundamentalsTechnical ScreenAgentic-WorkflowsEvaluationLLM-Systems
  • Applied IntuitionMediumMachine Learning Engineer
    Design Ordered CUDA Reduction

    This question evaluates understanding of parallel GPU programming, deterministic reduction ordering, and numerical stability in floating-point arithmetic, within the domain of parallel algorithms, GPU/CUDA programming, and numerical computing for a Software Engineering Fundamentals / Machine Learning Engineer role.

    Software Engineering FundamentalsTechnical Screen
  • Capital OneEasyMachine Learning Engineer
    How would you improve card-type detection?

    This question tests your ability to design a modular and maintainable classification system that identifies credit card networks (e.g., Visa, Mastercard) based on raw input data while considering validation and error handling.

    Software Engineering FundamentalsOnsiteData ValidationString ManipulationSystem Design
  • CohereMediumMachine Learning Engineer
    Build an LLM-driven text-game agent

    This question tests the ability to design a robust pipeline for an LLM-based agent interacting with a stateful environment, focusing on context management, output validation, and error recovery.

    Software Engineering FundamentalsOnsiteLLMPrompt EngineeringSystem Design
  • CohereMediumMachine Learning Engineer
    Replace a Heuristic Terminal Text Game's Python Logic With LLM Calls

    A live coding round: replace the heuristic Python implementation of a terminal text game with one driven by an LLM while keeping the game playable end to end. AI assistants are allowed, but the round judges your own implementation and debugging, including validating model output, fallbacks, and tests with a fake model.

    Software Engineering FundamentalsOnsite
  • FurtheraiMediumMachine Learning Engineer
    Build a Create/Execute Workflow Service With an AI Assistant: Plan, Implement, Verify

    A 45-minute practical coding exercise: build a small service with create-workflow and execute-workflow APIs while using an AI coding assistant. It evaluates planning, implementing and verifying with the assistant, along with validation of workflow definitions, dependency-ordered execution and step failure handling.

    Software Engineering FundamentalsOnsite
  • GatikHardMachine Learning Engineer
    Design a YAML-Configured Point-Cloud Transformation Pipeline

    Tests software engineering fundamentals and clean object-oriented design in Python by building an extensible, schema-validated point-cloud transformation pipeline with registry patterns and metadata tracking.

    Software Engineering FundamentalsTechnical ScreenObject-Oriented DesignPoint CloudData Pipelines
  • GleanMediumMachine Learning Engineer
    AI-Paired Rate-Limited Wikipedia Crawler That Prioritizes Unseen Title Initials

    Pair with an AI coding assistant to build a rate-limited Wikipedia crawler that first crawls pages whose title initial has not yet been covered, then crawls randomly once all 26 letters are done. Tests frontier design, link normalization, rate limiting and disciplined use of AI-generated code.

    Software Engineering FundamentalsOnsite
  • LilaMediumMachine Learning Engineer
    Debug a Transformer bug in an unfamiliar repo

    This question tests your ability to identify and rectify a logical error in a Transformer's multi-head self-attention mechanism, specifically focusing on tensor dimensionality, causality masking, and numerical stability.

    Software Engineering FundamentalsOnsiteTransformersDeep LearningDebugging
  • MicrosoftMediumMachine Learning Engineer
    Compute precision/recall from a flaky top-k API

    This question evaluates understanding of binary classification evaluation metrics (precision and recall) and competency in handling unreliable API behavior for robust metric computation, testing both conceptual understanding and practical application.

    Software Engineering FundamentalsTechnical Screen
  • MicrosoftMediumMachine Learning Engineer
    Explain a project deeply

    This question assesses the candidate's depth of ownership over a previous machine learning project, specifically testing their ability to articulate system design choices, technical trade-offs, and operational resilience.

    Software Engineering FundamentalsOnsiteSystem DesignMLOpsArchitecture
  • OpenAIHardMachine Learning Engineer
    Analyze matrix multiplication complexity

    This question evaluates understanding of time and space complexity for matrix multiplication and memory accounting in ML workloads, testing competency in asymptotic analysis, linear algebra operations, and resource estimation.

    Software Engineering FundamentalsTechnical Screen
  • OpenAIMediumMachine Learning Engineer
    Debug a Concurrent Job Scheduler

    This question evaluates debugging and hardening skills for concurrent systems, focusing on detection and reasoning about race conditions, deadlocks, lock-contention hotspots, state-machine invariant enforcement, rate-limiting, retry semantics, and instrumentation for per-job metrics in a job scheduler.

    Software Engineering FundamentalsTechnical Screen
  • OpenAIHardMachine Learning Engineer
    Design an Extensible Simulation Engine

    This problem tests object-oriented design patterns and modular architecture by requiring the implementation of a simulation engine that remains agnostic to the specific rules of a two-player turn-based game.

    Software Engineering FundamentalsOnsiteSystem DesignObject-Oriented DesignDesign Patterns
  • OpenAIHardMachine Learning Engineer
    Design an In-Memory Key-Value Cache

    Implement a thread-safe in-memory key-value cache supporting capacity bounds, LRU eviction, and per-key time-to-live (TTL) expiration.

    Software Engineering FundamentalsTechnical ScreenData StructuresConcurrencyLRU Cache
  • OpenAIMediumMachine Learning Engineer
    Explain KV cache in Transformer inference

    This question evaluates understanding of KV cache mechanisms in Transformer inference, including attention-state caching, memory and latency trade-offs, and engineering optimizations for autoregressive decoding.

    Software Engineering FundamentalsOnsite
  • OpenAIHardMachine Learning Engineer
    Explain what torch.distributed.barrier does

    This question evaluates understanding of PyTorch distributed synchronization primitives, process coordination, and concurrency control in distributed training workflows.

    Software Engineering FundamentalsOnsite
  • OpenAIMediumMachine Learning Engineer
    Model Infection, Immunity, Delayed Death, and Burn Interventions on a Grid

    Design and implement a discrete grid simulation modeling a five-stage disease progression with state countdowns, immunity, delayed mortality, and external burn interventions.

    Software Engineering FundamentalsTechnical Screensimulationmatrixstate-machine
  • RedditEasyMachine Learning Engineer
    Design a Tennis Scoring System

    This problem tests your ability to model state transitions, encapsulate logic using object-oriented principles, and implement conditional rule-based scoring in a competitive game.

    Software Engineering FundamentalsTechnical ScreenObject-Oriented DesignState MachineLogic
  • ShopifyMediumMachine Learning Engineer
    Build an Automatic Refund Decision System in a Pair-Programming Session

    A pair-programming exercise to build an automatic refund system for an online store, combining light system design with working code across several incremental steps. It tests domain modeling, pluggable eligibility rules, preventing over-refunds and duplicate payouts on retries, and explaining design choices as you code.

    Software Engineering FundamentalsTechnical Screen
  • SnowflakeMediumMachine Learning Engineer
    Design and Implement a Rate Limiter with an AI Assistant, Then Defend and Test It

    Design and implement a rate limiter in an AI-assisted coding round: choose and defend an algorithm against its alternatives, direct an AI assistant to write the code, review it and test it. It tests rate-limiting algorithm trade-offs, concurrency, time handling and critical review of generated code.

    Software Engineering FundamentalsOnsite
  • Startups.ComMediumMachine Learning Engineer
    Debug and scale a PyTorch training loop

    This question evaluates debugging and performance engineering skills for deep learning training pipelines, including diagnosing convergence and instability issues in PyTorch, scaling training with Fully Sharded Data Parallel (FSDP), designing sparse gradient all-reduce communication patterns, and judging when to implement custom CUDA/Triton kernels. Commonly asked for Machine Learning Engineer roles within the Software Engineering Fundamentals domain, it assesses both conceptual understanding of numerical stability and distributed systems and practical application skills in configuring multi-GPU training, communication trade-offs, and low-level performance and correctness validation.

    Software Engineering FundamentalsOnsite
  • TikTokMediumMachine Learning Engineer
    Explain Transformer, GPT vs BERT, and PR metrics

    This question evaluates understanding of modern NLP model architecture and evaluation metrics, specifically Transformer block components, key distinctions between GPT and BERT including pretraining objectives and usage, and precision/recall interpretation, testing competencies in deep learning architecture knowledge, model selection reasoning, and metric-based evaluation within the Software Engineering Fundamentals domain for a Machine Learning Engineer role. It is commonly asked because it probes both conceptual understanding of architectures and pretraining paradigms and practical application of performance trade-offs—assessing conceptual understanding alongside practical application in threshold-based precision versus recall decisions.

    Software Engineering FundamentalsTechnical Screen
  • VoleonHardMachine Learning Engineer
    Build a Tool-Using Weather Assistant

    Design a grounded weather assistant with typed model tool calls, server-side credentials, validated live data, provenance, and safe failure behavior.

    Software Engineering FundamentalsTechnical Screen
  • WaymoMediumMachine Learning Engineer
    Optimize Tensor Runtime Kernels

    This question evaluates competency in optimizing machine learning framework runtimes for accelerators, covering profiling and performance analysis of tensor kernels, memory layout design, operator scheduling and kernel fusion while weighing trade-offs among throughput, latency, memory usage, numerical correctness, and maintainability.

    Software Engineering FundamentalsTechnical Screen
  • ZiprecruiterEasyMachine Learning Engineer
    Debug Feature Updates in a Laptop Management CLI

    Implement and debug a stateful command-line interface processor that tracks device feature configurations, updates targeted laptops without state leakage across devices, and rolls back on validation failures.

    Software Engineering FundamentalsTechnical ScreenState ManagementCLIData Structures
  • xAIMediumMachine Learning Engineer
    Dynamic Batching Decode Loop for a Mock Language Model with Slot Refilling

    An LLM inference coding question: write the generation loop for a mock language model that returns one next token per sequence in a batch. Requests finish at different steps on a stop token or a max-token limit, and freed batch slots must be refilled from a waiting queue, testing state tracking and batching logic.

    Software Engineering FundamentalsOnsite
  • xAIMediumMachine Learning Engineer
    Find All Faulty GPU Nodes with Parallel Group Tests That Cannot Share Nodes

    An algorithm design question about finding every faulty GPU node when the only tool is a group test that fails if any node in the set is bad. Tests need at least two nodes and parallel tests cannot share nodes, so it tests adaptive testing strategies, identifiability, and cost in rounds and tests.

    Software Engineering FundamentalsOnsite
  • xAIMediumMachine Learning Engineer
    What are processes vs threads?

    This question evaluates understanding of concurrency concepts—processes versus threads—including memory/address-space management, shared-memory versus inter-process communication, performance trade-offs for CPU-bound versus I/O-bound workloads, and failure/isolation implications such as crash containment.

    Software Engineering FundamentalsOnline Assessment