Katkat

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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 4141–4170 of 4616 results

  • TikTokMediumSoftware Engineer
    Write complex SQL for cohorts and retention

    This question evaluates advanced SQL and data-engineering competencies such as cohort and retention analysis, deduplication, timezone normalization, last-touch attribution, aggregate revenue calculations, and effective use of window functions in the Data Manipulation (SQL/Python) domain.

    Data Manipulation (SQL/Python)Technical Screen
  • TmlMediumSoftware Engineer
    Implement a Resizable Deque

    This question evaluates proficiency in data structures and array-based implementations, specifically building a resizable double-ended queue (deque) backed by a circular array and understanding amortized O(1) operation costs.

    Coding & AlgorithmsTechnical Screen
  • ToastHardSoftware Engineer
    Code Review of a Multi-File HTTP API: Wrong Method, Payload and Validation Bugs

    A code-review exercise on several files that implement an HTTP API, where the known defects include a GET endpoint that should be POST, a request payload problem and missing input validation. It tests explaining each defect by its impact, fixing it consistently across files, and running a prioritized review within an hour.

    Software Engineering FundamentalsTechnical Screen
  • ToastHardSoftware Engineer
    Design a Restaurant Seat and Table Reservation System

    A system design question asking for a restaurant seat reservation system in which diners search availability by party size and time, then book, change or cancel. It tests the table-and-time inventory model, preventing double booking under concurrent requests, holds, availability caching and partitioning by restaurant.

    System DesignTechnical Screen
  • Together AIHardSoftware Engineer
    Design a GPU-aware pod scheduler

    This interview question evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer for Design a GPU-aware pod scheduler states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    System DesignTechnical Screen
  • Together AIMediumSoftware Engineer
    Detect cycles and break them in pod dependencies

    This question evaluates proficiency with directed graph concepts and dependency resolution, focusing on cycle detection and selecting a single dependency edge whose removal renders the graph acyclic.

    Coding & AlgorithmsTechnical Screen
  • Together AIEasySoftware Engineer
    Diagnose CPU Performance Problems on a Linux Server

    Diagnose Linux CPU slowness from host and thread metrics through scheduling, limits, profiles, and a workload-linked verification of the bottleneck.

    Software Engineering FundamentalsTechnical Screen
  • Together AIEasySoftware Engineer
    Diagnose Slow Network Throughput Including Containers

    Investigate slow network throughput across application, transport, host, and container layers using controlled comparisons, retransmissions, limits, and path behavior.

    Software Engineering FundamentalsTechnical Screen
  • Together AIEasySoftware Engineer
    Diagnose Storage I/O Performance and Identify the Workload

    Diagnose storage slowness using device metrics, process attribution, workload shape, cache and durability effects, and measurements appropriate to the storage stack.

    Software Engineering FundamentalsTechnical Screen
  • Together AIMediumSoftware Engineer
    Historical Lookups in a Timestamped Key-Value Store

    Implement historical key-value lookups using timestamped writes, per-key ordered histories, and binary search for the latest eligible value.

    Coding & AlgorithmsTechnical Screen
  • Together AIEasySoftware Engineer
    Investigate a Server Saturated by Logging

    Trace logging-related server saturation through resource attribution, producer/sink behavior, bounded queues, rotation and retention, and verified mitigation.

    Software Engineering FundamentalsTechnical Screen
  • Together AIMediumSoftware Engineer
    Schedule GPU Pods and Drain a Node

    Implement a GPU cluster manager to schedule workloads using a deterministic best-fit policy and simulate draining a node to check if all its pods can be migrated without disrupting other nodes.

    Coding & AlgorithmsTechnical ScreenGreedySimulationSystem Design
  • Together AIEasySoftware Engineer
    Split a Chunked Text Stream into Line-Balanced Parts

    Construct any balanced whole-line partition of a chunked text stream, preserving exact content and newline rules while explaining buffering and streaming limits.

    Coding & AlgorithmsTechnical Screen
  • TomaEasyFrontend Engineer
    Approximate Pi from Random Points

    This question evaluates a candidate's understanding of Monte Carlo estimation, basic Euclidean geometry, probability, and numerical reasoning when using random sampling to approximate mathematical constants.

    Coding & AlgorithmsTechnical Screen
  • TomaEasyFrontend Engineer
    Identify the CSS color function

    This question evaluates a candidate's understanding of CSS color functions, specifically knowledge of channel-based color specification and the use of an optional opacity component.

    Software Engineering FundamentalsTechnical Screen
  • TomaMediumSoftware Engineer
    Implement AudioStream Mixer

    This problem tests your ability to manage temporal data and stateful buffers by implementing a class that merges multiple incoming audio streams into a single output track using overwrite-based mixing logic.

    Coding & AlgorithmsTechnical ScreenHashMapsData StructuresSimulation
  • TomaEasyFrontend Engineer
    Which CSS function supports opacity?

    This question tests your knowledge of modern CSS color syntax and the various ways to define transparency within style rules.

    Software Engineering FundamentalsTechnical ScreenCSSFrontendStyling
  • Tools For HumanityEasyData Scientist
    Compute reply-based engagement metrics

    This question evaluates proficiency in data manipulation and analytics, emphasizing SQL/Python skills for temporal filtering, joins between posts and users, deduplication, aggregation (distinct counts), and percentage calculations used to compute reply-based engagement metrics.

    Data Manipulation (SQL/Python)Technical Screen
  • Tools For HumanityEasyData Scientist
    Detect and evaluate "stolen" posts

    This question evaluates data-science competencies in instrumentation and feature design, content-similarity detection and labeling, causal inference for experiments, measurement of harms, and model evaluation, and belongs to the Analytics & Experimentation domain.

    Analytics & ExperimentationTechnical Screen
  • TowerHardData Scientist
    Debug Oscillating GPU Utilization During Training

    Design a systematic debugging and architectural remediation strategy for a distributed deep learning training cluster exhibiting severe GPU utilization oscillation between 90% and 20%.

    ML System DesignTechnical Screendistributed-trainingml-system-designgpu-optimization
  • TowerHardData Scientist
    Explain Why Constant Neural-Network Initialization Fails

    This question tests the conceptual understanding of weight initialization strategies and the symmetry-breaking property required for neural network gradient-based optimization.

    Machine LearningTechnical ScreenDeep LearningInitializationOptimization
  • TowerMediumMachine Learning Engineer
    Explain the KV Cache and Prefill-Decode Disaggregation in LLM Serving

    Explain how the KV cache speeds up autoregressive decoding in transformer language models, estimate how much GPU memory it needs, and describe prefill-decode disaggregation in LLM serving. It tests understanding of compute-bound versus memory-bound inference phases, cache sizing and the trade-offs of splitting the phases across GPU pools.

    Machine LearningTechnical Screen
  • TransunionMediumData Scientist
    Describe past project experience clearly

    This prompt evaluates a candidate's competencies in applied data science tools and practices—including proficiency in Python or R, SQL querying and data transformation, problem scoping under ambiguity, technical-to-nontechnical communication, and team coordination.

    Behavioral & LeadershipTechnical Screen
  • TransunionEasyData Scientist
    How would you answer a DS video interview?

    TransUnion's Data Scientist Intern technical screen is an asynchronous video interview with five ~2-minute prompts covering Python/R problem solving, SQL usage, working under ambiguity, explaining technical work to non-technical stakeholders, and keeping a team aligned. This guide gives a per-prompt structure, the evaluator rubric, strong sample outlines, and the common mistakes to avoid.

    Behavioral & LeadershipTechnical Screen
  • TrexquantMediumSoftware Engineer
    C++ Fundamentals: const Pointers, and map vs unordered_map

    This question evaluates a candidate's grasp of C++ fundamentals, specifically const-correctness with pointers and the distinction between ordered and hash-based associative containers. It tests conceptual understanding of pointer semantics and data structure trade-offs (tree vs. hash table complexity and ordering), a common check in language-fundamentals interview rounds.

    Software Engineering FundamentalsTechnical Screen
  • TrexquantMediumSoftware Engineer
    Streaming Median Tracker

    This question evaluates a candidate's ability to design a data structure that maintains a running median over a stream of numbers, testing knowledge of heaps and balanced data partitioning. It is a classic coding and algorithms interview problem used to assess understanding of amortized time complexity and efficient online statistics tracking, requiring practical implementation rather than just conceptual discussion.

    Coding & AlgorithmsTechnical Screen
  • TripStackMediumSoftware Engineer
    Compute minimum resources for overlapping intervals

    This question evaluates understanding of interval overlap reasoning, resource-allocation and scheduling concepts, and proficiency with algorithmic complexity and appropriate data structure choices.

    Coding & AlgorithmsTechnical Screen
  • TripStackHardSoftware Engineer
    Explain Go concurrency and database choices

    This question evaluates a candidate's understanding of Go concurrency primitives and scheduler behavior, cross-language concurrency comparisons, database model trade-offs (relational, document, columnar, key–value), and end-to-end storage design for high-concurrency systems.

    System DesignTechnical Screen
  • TubiMediumData Scientist
    Compute daily net users from event logs

    This question evaluates SQL-based data manipulation skills focused on daily aggregation, cohort and retention calculations, deduplicating event records, and grouping metrics by device_platform.

    Data Manipulation (SQL/Python)Technical Screen
  • TubiHardData Scientist
    Determine A/B test sample size drivers

    This question evaluates statistical power and sample size determination for A/B testing, covering hypothesis testing for proportions, derivation using normal approximations, the impact of MDE, α and power choices, allocation ratios, cluster design (ICC and design effect), group‑sequential monitoring, and adjustment for overdispersed count outcomes.

    Analytics & ExperimentationTechnical Screen