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 1411–1440 of 3640 results

  • GoogleHardSoftware Engineer
    Design an elevator control system

    This question evaluates system design skills including architectural modeling of components, scheduling and concurrency control, state-machine design, and fault-tolerance for real-time control systems, and falls under the System Design domain.

    System DesignOnsite
  • GoogleEasySoftware Engineer
    Design compressed vector and compute dot product

    This problem tests your ability to design a memory-efficient data structure for sparse or repetitive vector data and implement an arithmetic operation without fully decompressing the representation.

    Coding & AlgorithmsOnsiteArraysTwo PointersData Structures
  • GoogleHardMachine Learning Engineer
    Design feedback-driven recommender

    Design feedback-driven recommender 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 DesignOnsite
  • GoogleHardData Scientist
    Design human review to estimate model accuracy

    This interview question evaluates statistical assumptions, formulas, estimation strategy, uncertainty, edge cases, and interpretation in a realistic interview setting. A strong answer for Design human review to estimate model accuracy states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Statistics & MathOnsite
  • GoogleHardMachine Learning Engineer
    Design large-scale near-duplicate video detection

    This question tests the ability to design an end-to-end pipeline for detecting near-duplicate videos at a massive scale, focusing on embedding generation, vector indexing, and trade-offs between precision and recall.

    System DesignOnsiteComputer VisionEmbeddingsANN Search
  • GoogleMediumSoftware Engineer
    Design structure for insert and k-th largest

    This problem tests your ability to design a dynamic data structure that maintains elements while efficiently querying the k-th largest value, necessitating a balance between insertion speed and retrieval performance.

    Coding & AlgorithmsOnsiteData StructuresHeapBinary Search Tree
  • GoogleEasyData Scientist
    Design tests to measure latency impact

    A Google Data Scientist onsite case on measuring the causal impact of reduced YouTube video-start latency on engagement. It spans A/B design (primary metric, diagnostics, error/buffering guardrails), randomization unit and interference, power/MDE for heavy-tailed watch time, variance reduction (CUPED, stratification), analysis of conflicting movements, ratio-metric decomposition with Simpson’s paradox, and propensity score matching when randomization isn’t possible.

    Analytics & ExperimentationOnsite
  • GoogleMediumSoftware Engineer
    Determine All Players with Fixed Rankings

    Determine which players in a competition have a uniquely determined ranking given a set of pairwise match outcomes.

    Coding & AlgorithmsOnsitegraphbfsdfs
  • GoogleMediumSoftware Engineer
    Determine Whether a Word Exists in a Graph

    This problem tests the ability to implement a depth-first search (DFS) with backtracking to find a specific sequence within a grid, while managing state to avoid reusing the same path.

    Coding & AlgorithmsOnsiteDFSBacktrackingGraphs
  • GoogleMediumSoftware Engineer
    Determine validity after digit-constrained deletions

    This interview question evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer for Determine validity after digit-constrained deletions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Coding & AlgorithmsOnsite
  • GoogleEasySoftware Engineer
    Deterministic Task Execution Order

    This question tests the ability to implement Kahn's algorithm for topological sorting while using a min-priority queue to satisfy specific tie-breaking requirements.

    Coding & AlgorithmsOnsiteGraphsTopological SortPriority Queue
  • GoogleMediumData Scientist
    Diagnose a metric drop in search time

    This question evaluates a data scientist's competency in precise metric and population definition, time‑to‑event and survival/hazard modeling, time‑series decomposition and change‑point analysis, instrumentation and traffic forensics, and experimental design for root‑cause identification.

    Analytics & ExperimentationOnsite
  • GoogleHardData Scientist
    Diagnose and reverse an adoption-rate decline

    This question evaluates a data scientist's competency in product analytics and experimentation, covering precise metric definition and validation, instrumentation and event quality checks, rapid triage of adoption regressions, hypothesis generation, experiment design, and causal inference.

    Analytics & ExperimentationOnsite
  • GoogleMediumSoftware Engineer
    Discuss Challenges, Difficult Colleagues, and Multitasking

    This question assesses your ability to navigate workplace friction and manage competing priorities through structured reflection and professional communication.

    Behavioral & LeadershipOnsiteBehavioralLeadershipConflict Resolution
  • GoogleMediumSoftware Engineer
    Earliest Time of Full Connectivity

    Determine the earliest timestamp at which all nodes in a network become part of a single connected component using a chronological sequence of edge additions.

    Coding & AlgorithmsOnsitegraphunion-findsorting
  • GoogleMediumSoftware Engineer
    Enforce a Country's IP Ban List on Incoming Connections Using Its Lookup API

    A system design exercise where a country provides an API reporting whether an IP address is banned and the service must refuse connections from banned addresses. It tests scoping questions such as IPv6 and address ranges, fast local enforcement at the edge, keeping ban data fresh, and fail-safe compliance behavior.

    System DesignOnsite
  • GoogleHardData Scientist
    Estimate Population Mean and Conversion Rate Accurately

    Evaluates core statistical inference skills across p-values, confidence intervals, standard error reduction, tail probability estimation, efficient conversion-rate sampling, and truncated-normal estimation. Strong answers state assumptions, use appropriate intervals and weights, and avoid common interpretation errors.

    Statistics & MathOnsite
  • GoogleHardSoftware Engineer
    Event Topic Router With Named Placeholders and Tail Wildcards

    Build a router for a telemetry message bus that maps dot-separated topics to registered subscription patterns with named placeholders and a trailing multi-segment wildcard; tests trie design, precedence rules and backtracking.

    Software Engineering FundamentalsOnsitetriebacktrackingstring-parsing
  • GoogleMediumSoftware Engineer
    Explain Changing Priorities and Your Role on a Team

    Use concrete examples to explain how you respond to a material priority change and what contribution teammates reliably seek from you. Strong responses show explicit trade-offs, stakeholder alignment, adaptable collaboration, measurable impact, honest limits, and lessons carried forward.

    Behavioral & LeadershipOnsite
  • GoogleHardMachine Learning Engineer
    Explain ML model fundamentals

    Explain ML model 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 DesignOnsite
  • GoogleHardFrontend Engineer
    Explain Motivation for an Experimental Technology Team

    Craft a credible motivation answer for an experimental technology team by connecting mission interest with evidence-driven, responsible execution.

    Behavioral & LeadershipOnsite
  • GoogleMediumData Scientist
    Explain P-values and Confidence Intervals in Simple Linear Regression

    Review p-values, confidence intervals and slope inference in simple linear regression, including assumptions and causal limits.

    Statistics & MathOnsite
  • GoogleHardSoftware Engineer
    Explain SLI/SLO/SLA and design monitoring

    This question evaluates a candidate's competency in service reliability and observability, specifically understanding and distinguishing SLIs, SLOs, and SLAs, planning error budgets, and designing monitoring and alerting for a production web API.

    Software Engineering FundamentalsOnsite
  • GoogleMediumSoftware Engineer
    Explain What You Would Do Differently

    This question assesses a candidate's ability to demonstrate professional growth, self-awareness, and the capacity to synthesize past mistakes into improved engineering practices.

    Behavioral & LeadershipOnsiteBehavioralSelf-ReflectionLeadership
  • GoogleMediumSoftware Engineer
    Explain Your Most Meaningful Project Contribution

    Prepare a project story that makes your most meaningful contribution and personal ownership clear. Explain one consequential decision, its tradeoffs and obstacles, how you evaluated the outcome, and why the work still matters.

    Behavioral & LeadershipOnsite
  • GoogleMediumSoftware Engineer
    Explain Your Most Technically Complex Project

    This question assesses the candidate's ability to articulate complex technical challenges, justify architectural design decisions, and communicate the impact of their personal contributions in a collaborative environment.

    Behavioral & LeadershipOnsiteBehavioralSystem DesignLeadership
  • GoogleHardData Scientist
    Explain a favorite model end-to-end

    This question evaluates a candidate's end-to-end machine learning competencies, including problem framing, objective and loss selection, inductive biases, feature engineering, validation strategies, training and regularization practices, production issues, monitoring, and fairness/privacy considerations.

    Machine LearningOnsite
  • GoogleMediumSoftware Engineer
    Explain handling a tight project deadline

    This question evaluates time management, prioritization, communication, teamwork, and leadership competencies in delivering technical work under pressure.

    Behavioral & LeadershipOnsite
  • GoogleEasyData Scientist
    Explain mixed models and fixed vs random effects

    This question evaluates understanding of mixed effects models, the conceptual distinction between fixed and random effects, interpretation of coefficients and variance components, and awareness of practical pitfalls when modeling hierarchical or panel data.

    Statistics & MathOnsite
  • GoogleMediumProduct Manager
    Favorite Products & Improvement Metrics

    Practice a PM onsite prompt about products you worked on, admired products, and improvement metrics. The guide covers product storytelling, North Star and input metrics, product taste, a non-tech improvement example, primary and guardrail metrics, and practical experiment design.

    Product / Decision MakingOnsite