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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.
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Showing 4471–4500 of 9403 results
- LinkedInMediumData ScientistCompare queueing systems and common distributions
LinkedIn data scientist statistics screen covering pooled versus separate queues, height distributions and mixture distributions, right-skewed network degree, mean-median-mode ordering, and L1/L2 regularization bias.
Statistics & MathTechnical Screen - LinkedInEasyData ScientistCompute each member’s current notification status
A LinkedIn data scientist SQL screen: given an end-of-January notification-status snapshot and a February log of turn_on/turn_off actions, compute each member's current status as of 2020-02-29, keeping members from either table. Follow-ups explore reconstructing state when the action log has no date column — unsolvable in general, but recoverable via action-count parity when every action is a guaranteed valid transition.
Data Manipulation (SQL/Python)Technical Screen - LinkedInMediumSoftware EngineerCompute graph distance and impacted services
This problem tests your ability to model a directed dependency graph and perform reachability analysis to identify all downstream services affected by a change in a root service.
Coding & AlgorithmsOnsiteGraphsBFSDFS - LinkedInEasyMachine Learning EngineerCompute point-to-segment minimum distance
This problem tests your ability to apply vector projections and geometric constraints to find the shortest distance from a point to a line segment in a 2D plane.
Coding & AlgorithmsTechnical ScreenGeometryVectorsMath - LinkedInMediumMachine Learning EngineerCompute total covered interval length
Compute total covered interval length evaluates algorithm design, data structures, correctness, complexity, edge cases, and implementation details in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Coding & AlgorithmsTechnical Screen - LinkedInMediumData ScientistCount Article Types Viewed
Count Article Types Viewed evaluates SQL or pandas logic, joins, grouping, window functions, null handling, edge cases, and validation in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Data Manipulation (SQL/Python)Technical Screen - LinkedInMediumSoftware EngineerCount Distinct Values in a Huge Sorted Array
This problem tests your ability to optimize search operations in a sorted array by using binary search to skip redundant elements, achieving sub-linear time complexity relative to the total array size.
Coding & AlgorithmsOnsiteBinary SearchArraysOptimization - LinkedInMediumSoftware EngineerCount Subsequences Whose Minimum Plus Maximum Stays Within a Target
Count the non-empty subsequences of an integer array whose minimum plus maximum is at most a target, returning the count modulo 10^9 + 7. Tests combinatorial counting, careful handling of duplicate values chosen by index, and modular arithmetic for very large totals.
Coding & AlgorithmsOther - LinkedInMediumSoftware EngineerCount connected land components in a grid
This question evaluates understanding of grid traversal and graph connectivity concepts, focusing on modeling a 2D matrix as adjacency relationships within the coding and algorithms domain.
Coding & AlgorithmsOnsite - LinkedInMediumSoftware EngineerCount islands and distinct shapes
This question evaluates a candidate's understanding of grid-based graph traversal and connected-component detection, along with the ability to recognize and canonicalize distinct island shapes.
Coding & AlgorithmsOnsite - LinkedInEasySoftware EngineerDebug Queues and Solve Arrays
Tests array traversal, sliding window techniques, and handling wrap-around logic in circular data structures with edge cases.
Coding & AlgorithmsOnsiteArraySliding WindowTwo Pointers - LinkedInMediumData ScientistDerive expectation for two consecutive heads
This question evaluates mastery of probability theory and stochastic processes, specifically expectation and variance calculations, Markov-chain or recurrence reasoning, and pattern waiting times in Bernoulli trials relevant for a Data Scientist role.
Statistics & MathTechnical Screen - LinkedInMediumData ScientistDerive mean and variance of x̄
This question tests your ability to derive the expected value and variance of the sample mean for a sequence of random variables, accounting for the effect of correlation between them.
Statistics & MathTechnical ScreenStatisticsVarianceExpectation - LinkedInMediumSoftware EngineerDescribe challenging teamwork and feedback handling
Describe challenging teamwork and feedback handling 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 & LeadershipOnsite - LinkedInMediumSoftware EngineerDescribe leading an infrastructure initiative
This interview question evaluates behavioral evidence, ownership, communication, trade-offs, and measurable outcomes in a realistic interview setting. A strong answer for Describe leading an infrastructure initiative states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
Behavioral & LeadershipOnsite - LinkedInHardData ScientistDesign Experiments for Email Campaign & Messaging Update
Evaluates experiment design for concurrent email and in-product messaging launches with possible interaction effects. Strong answers use factorial designs, power calculations, interaction terms, sequential testing, and guardrails.
Analytics & ExperimentationOnsite - LinkedInMediumSoftware EngineerDesign Keyword Search over Posts with Exclusions and Frequency Ranking
A system design question on keyword search over social posts: find the posts that contain a keyword without scanning them all, support queries that require one keyword and exclude another, and order results by how often the keywords appear. Tests indexing, query evaluation, sharding, pagination and ranking trade-offs.
System DesignOnsite - LinkedInMediumMachine Learning EngineerDesign LinkedIn Learning course recommendations
The question evaluates proficiency in end-to-end machine learning system design, covering feature engineering from job post text, candidate generation and ranking, model training and labeling, evaluation metrics, and production concerns such as cold start, bias, and feedback loops.
ML System DesignOnsite - LinkedInEasySoftware EngineerDesign O(1) Randomized Multiset
This problem tests your ability to design a data structure that supports efficient insertion, deletion, and uniform random sampling by combining dynamic arrays with hash maps to achieve constant time complexity.
Coding & AlgorithmsTechnical ScreenHash MapArrayDesign - LinkedInHardSoftware EngineerDesign Top K ranking system
Design Top K ranking system evaluates requirements, scale assumptions, API/data design, architecture, trade-offs, failure modes, and rollout in a realistic interview setting. A strong answer states assumptions, handles edge cases, explains trade-offs, and shows how to validate the result clearly.
System DesignOnsite - LinkedInMediumDevOps EngineerDesign a CI Job Scheduler with Live Build Output
Design a scalable continuous integration (CI) platform that schedules dependency-aware build jobs across worker fleets and streams live console output to end users.
System DesignOnsiteCI/CDDistributed SystemsDevOps - LinkedInMediumSoftware EngineerDesign a CI/CD Task Scheduler
Design the core distributed task scheduling engine for an enterprise CI/CD platform that coordinates DAG-based workflows across heterogeneous worker pools.
System DesignOnsiteDistributed SystemsTask SchedulingCI/CD - LinkedInMediumSoftware EngineerDesign a Calendar System
Tests your ability to design a scalable calendar backend that supports single and recurring events, attendee invitations, and time-based reminder notifications with timezone awareness.
System DesignTechnical ScreenDistributed SystemsData ModelingScheduling - LinkedInMediumSoftware EngineerDesign a Distributed Key-Value Store for a Small Company's Internal Use
Design a distributed key-value store for internal use at a small company. The question tests comparing centralized, decentralized and hybrid architectures, and depth on partitioning, rebalancing, replication, failure handling, consistency, hot keys and availability at a senior infrastructure level.
System DesignOnsite - LinkedInMediumSoftware EngineerDesign a Global Calendar Service
This question evaluates competence in designing scalable, time-zone aware calendaring systems, covering API and data model design, recurrence representation, daylight saving semantics, conflict detection, storage strategy, and consistency trade-offs.
System DesignOnsite - LinkedInHardMachine Learning EngineerDesign a Model That Predicts Whether a Member Clicks a Displayed Job
An ML system design question: predict whether a member will click a job displayed to them, using member features, job content and interaction history. It tests defining the supervision signal and training data, choosing a loss, preventing data leakage, building member and job embeddings, and laying out the training and serving components.
ML System DesignTechnical Screen - LinkedInHardSoftware EngineerDesign a Multi-Region Malicious-IP Detection System
Design a globally distributed, low-latency edge security service that detects and blocks malicious IP addresses across regions, featuring decentralized evaluation, asynchronous intelligence sharing, and rapid false-positive rollback.
System DesignTechnical ScreenDistributed SystemsSecurityLow Latency - LinkedInMediumMachine Learning EngineerDesign a Personalized Feed and Compare Ranking Objectives
Design an end-to-end personalized professional feed system and compare pointwise, pairwise, and listwise learning-to-rank formulations across offline training, online serving, and business metrics.
ML System DesignTechnical Screenml-system-designrecommendation-systemslearning-to-rank - LinkedInMediumSoftware EngineerDesign a Personalized Job Suggestions Page for LinkedIn Members
Design the LinkedIn page that suggests open jobs to a signed-in member, from candidate retrieval and filtering to ranking, pagination and serving. Tests large-scale recommendation architecture, freshness for new and closed postings, feedback logging, latency budgets and graceful degradation.
System DesignOnsite - LinkedInMediumSoftware EngineerDesign a Raffle Drum That Draws Duplicate Tickets Fairly in O(1)
Design a drum that holds raffle ticket codes, where the same code can be dropped in more than once, and supports adding a ticket, pulling a specific ticket out, and drawing one at random so every physical ticket in the drum is equally likely to come out — all in average O(1) time. Tests combining an array with a hash index so removal and random draw both stay constant time even with string keys and duplicates.
Software Engineering FundamentalsTechnical Screendesignhash-maprandomization
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