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 5971–6000 of 9403 results

  • NetflixMediumSoftware Engineer
    Recommend New Friends from a Mutual-Friendship Graph and Scale the Approach

    A problem-solving question about recommending new friends from a mutual friendship graph, worked mostly through discussion with a little code and pseudocode. It tests candidate generation and scoring with deterministic tie-breaks, cost in terms of node degree, handling highly connected users, and precomputing and refreshing suggestions at scale.

    Software Engineering FundamentalsOther
  • NetflixMediumSoftware Engineer
    Report Tree Levels and Balanced Subtrees

    Tests traversing a binary tree stored in array (heap) layout to compute subtree heights and identify nodes rooted at height-balanced subtrees along with their tree levels.

    Coding & AlgorithmsOnsitebinary-treeheapdepth-first-search
  • NetflixMediumSoftware Engineer
    Return the longest contiguous subarray with all distinct values

    This problem tests your ability to use the sliding window pattern and a hash map to maintain a range of unique elements efficiently in O(n) time.

    Coding & AlgorithmsTechnical ScreenSliding WindowHash MapArrays
  • NetflixMediumSoftware Engineer
    Return valid task order from prerequisites

    This question evaluates proficiency in graph algorithms, notably topological sorting and cycle detection, as well as algorithmic complexity analysis and handling of dependency constraints.

    Coding & AlgorithmsOnsite
  • NetflixHardMachine Learning Engineer
    Review a Feature Pipeline PR for Production Risks, Then Serve Features by Freshness

    Review a feature pipeline pull request whose tests all pass and explain what could break once it runs in production, from time leakage and training-serving skew to data quality and scale. Then decide how the same features should be served when the model needs day-old, minute-fresh or request-time values.

    ML System DesignTechnical Screen
  • NetflixMediumSoftware Engineer
    Session Token Cache With Per-Entry Expiry and a Test Suite

    Implement an in-memory cache whose entries expire individually, reclaim memory for keys that are never read again, and prove it with deterministic tests using an injected clock. Tests expiry semantics, stale-entry handling and test design.

    Software Engineering FundamentalsTechnical Screendata-structuresheapcaching
  • NetflixMediumSoftware Engineer
    Show Behavioral Fit and Experience

    Show Behavioral Fit and Experience evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Behavioral & LeadershipHR Screen
  • NetflixMediumSoftware Engineer
    Show role fit using past ad experience

    This question evaluates a candidate's ability to demonstrate role fit by mapping past ads engineering projects to job requirements and communicating measurable impact, assessing competencies such as ownership, cross-functional collaboration, incident debugging, and prioritization.

    Behavioral & LeadershipOnsite
  • NetflixMediumSoftware Engineer
    Simulate a TTL Cache with LRU Eviction

    Implement a fixed-capacity key-value cache combining per-key TTL expiration with LRU eviction and O(1) average time per operation.

    Coding & AlgorithmsTechnical ScreenCacheLRUHash Table
  • NetflixEasyData Scientist
    Solve core probability and statistics questions

    This problem tests your understanding of the Central Limit Theorem and its application in power analysis for A/B testing and confidence interval estimation.

    Statistics & MathOnsiteProbabilityA/B TestingCentral Limit Theorem
  • NetflixMediumSoftware Engineer
    Solve non-repeating show substring

    This question evaluates understanding of sequence processing, uniqueness detection, and the use of auxiliary data structures to track previously seen elements when finding non-repeating contiguous subsequences, applied to show names instead of characters.

    Coding & AlgorithmsTechnical Screen
  • NetflixMediumSoftware Engineer
    Solve sliding-window and disjoint-string-pairs tasks

    This question tests the ability to combine sliding window techniques with bit manipulation or frequency counting to identify pairs of substrings that share no common characters.

    Coding & AlgorithmsTechnical ScreenStringsBit ManipulationSliding Window
  • NetflixMediumMachine Learning Engineer
    Transform flat keys into nested dictionary

    This question evaluates proficiency in parsing and restructuring hierarchical parameter keys into nested dictionary structures, string manipulation for grouping, handling nonconforming keys and duplicates, and reasoning about time and space complexity.

    Data Manipulation (SQL/Python)Technical Screen
  • NetflixMediumData Scientist
    Write SQL for rolling frequency caps

    This question evaluates proficiency with rolling-window analytics, frequency cap logic, time-based attribution, and per-user/per-campaign aggregation for advertising data.

    Data Manipulation (SQL/Python)Onsite
  • New RelicMediumBackend Engineer
    Compress a String by Run-Length Counts, Keeping the Original When Not Shorter

    Implement run-length string compression that replaces each run of repeated characters with the character and its count, returning the original string when the compressed form is not strictly shorter. Tests careful run handling, multi-digit counts, the tie rule, and complexity and edge-case discussion.

    Coding & AlgorithmsOnsite
  • New RelicMediumBackend Engineer
    Design a Kafka Consumer Service That Groups Trace Events by Trace ID

    Design a distributed service that consumes trace events from Kafka, groups every event sharing a trace ID, and hands each complete trace to an existing processing function. Covers partitioning, in-memory versus external state, deciding when a trace is complete, and traces that stay open for hours.

    System DesignOnsite
  • New RelicMediumBackend Engineer
    Longest Strictly Increasing Path in a Grid with Four-Directional Moves

    Given an integer matrix, find the number of cells on the longest path whose values strictly increase, moving only up, down, left, or right with no diagonal steps and no wrap-around at the edges. Tests grid search and the ability to turn a working first solution into an efficient one.

    Coding & AlgorithmsOnsite
  • NewrelicHardSoftware Engineer
    Maximum Path Sum in an Indexed Binary Tree

    This problem tests tree traversal techniques on an index-based representation, focusing on handling negative weights and memory efficiency via an iterative post-order approach.

    Coding & AlgorithmsTechnical ScreenBinary TreeDynamic ProgrammingIterative Traversal
  • NewrelicHardSoftware Engineer
    Product of Array Except Self Without Division

    This problem tests array manipulation skills and the ability to optimize space complexity by using prefix and suffix product passes instead of division.

    Coding & AlgorithmsTechnical ScreenArraysPrefix-SumOptimization
  • NewsBreakMediumMachine Learning Engineer
    Derive and implement calibration via temperature scaling

    This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Derive and implement calibration via temperature scaling states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Machine LearningTechnical Screen
  • NewsBreakHardMachine Learning Engineer
    Design approach for class imbalance

    This interview question evaluates core ML concepts, assumptions, math intuition, training/evaluation trade-offs, and practical failure modes in a realistic interview setting. A strong answer for Design approach for class imbalance states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Machine LearningTechnical Screen
  • NewsBreakMediumSoftware Engineer
    Find Optimal Piecewise Constant Regression Parameters

    This problem tests the ability to derive optimal constants for a piecewise regression model with a single split point and to implement an efficient search algorithm to minimize the sum of squared errors.

    Machine LearningTechnical ScreenRegressionOptimizationPrefix Sums
  • NewsBreakMediumMachine Learning Engineer
    Walk through a key project

    This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Walk through a key project states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Behavioral & LeadershipTechnical Screen
  • NexonMediumProduct Manager
    Handle Partner Pushback

    Answer a game PM behavioral question about handling cross-functional pushback from design, engineering, analytics, publishing, and monetization partners. The solution uses STAR structure, active listening, shared goals, player data, MVP options, guardrails, and decision clarity.

    Behavioral & LeadershipTechnical Screen
  • NexonMediumProduct Manager
    Investigate Item Usage Spike

    Investigate an in-game item usage spike by verifying instrumentation, segmenting players and item sources, building hypotheses across patches, economy shifts, promotions, exploits, and bots, then choosing actions with retention, economy, monetization, and trust guardrails.

    Product / Decision MakingTechnical Screen
  • NexonEasyProduct Manager
    Walk Through Your Background and Motivation

    Prepare Nexon PM background and motivation answers with a coherent career story, game-product relevance, STAR project examples, strengths, weaknesses, player outcomes, live-service thinking, and cross-functional product judgment.

    Behavioral & LeadershipHR Screen
  • NextdoorMediumMachine Learning Engineer
    Answer HR motivation and project experience questions

    This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Answer HR motivation and project experience questions states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.

    Behavioral & LeadershipTechnical Screen
  • NextdoorMediumMachine Learning Engineer
    Build Ranked Feed With Photo Batching

    This question evaluates algorithmic reasoning and data manipulation skills, including stable sorting, grouping/batching, and merging of ranked items while preserving ordering invariants.

    Coding & AlgorithmsTechnical Screen
  • NextdoorMediumMachine Learning Engineer
    Build a model using only pandas/numpy

    This question evaluates proficiency in applied machine learning competencies including data preprocessing, categorical encoding, feature scaling, implementing baseline models and optimization using numpy/pandas, and selecting appropriate evaluation metrics.

    Machine LearningTechnical Screen
  • NextdoorMediumMachine Learning Engineer
    Build an end-to-end ML classification pipeline

    This question evaluates a candidate's competency in building end-to-end tabular classification pipelines, including data loading and splitting, missing-value handling, categorical encoding, feature scaling, model training and comparison, hyperparameter tuning, metric-based evaluation, model persistence, and batch inference.

    ML System DesignTechnical Screen