LinkedIn interview questions

Showing 1–30 of 154 results

• Analyze homepage drop and feed rankingHard

  This question evaluates a candidate's competency in product analytics, causal diagnosis, instrumentation and logging validation, segmentation and cohort analysis, and experimental design for feed ranking and user-path behavior.

  LinkedInData ScientistAnalytics & ExperimentationTechnical Screen
• Analyze member video posting behavior by countryEasy

  A LinkedIn data scientist technical-screen question on member video-posting behavior using two relational tables. It tests joins, first-event derivation with MIN/GROUP BY, conditional grouping for US vs non-US comparison, and distinct-member counts per country with a length filter.

  LinkedInData ScientistData Manipulation (SQL/Python)Technical Screen
• Answer Repeated Shortest Word Distance QueriesEasy

  Design a data structure that preprocesses a list of words to efficiently answer repeated queries for the shortest index distance between two distinct words.

  LinkedInSoftware EngineerCoding & AlgorithmsTechnical Screen
• Answer practical ML foundations questionsMedium

  This question evaluates an interviewee's practical mastery of ML foundations, covering probability calibration and its evaluation, feature selection methods including neural-network approaches, tokenizer types and trade-offs in NLP, and optimizer behavior such as Adam's maintained statistics.

  LinkedInMachine Learning EngineerMachine LearningOnsite
• Arrange Nonnegative Integers to Form the Largest NumberEasy

  Tests custom sorting logic and string manipulation to arrange a list of nonnegative integers into the lexicographically largest combined numerical string.

  LinkedInSoftware EngineerCoding & AlgorithmsTechnical Screen
• Block Malicious IPs at an API Gateway Across Data CentersMedium

  Design gateway IP-block enforcement with trusted client addresses, versioned rules, fast local checks, expiration, and multi-data-center propagation.

  LinkedInSoftware EngineerSystem DesignOnsite
• Can You Place N Objects?Medium

  This problem tests your ability to handle greedy array traversal while maintaining specific adjacency constraints, requiring careful management of boundary indices.

  LinkedInSoftware EngineerCoding & AlgorithmsTechnical Screen
• Check Whether a String Is a Signed Decimal Number Without Exponent NotationMedium

  Write a function that decides whether a string is a valid plain decimal number with an optional sign and fractional part, rejecting exponents, stray symbols, and repeated decimal points. It tests turning a small grammar into careful character-by-character validation and covering edge cases such as empty strings and bare signs.

  LinkedInSoftware EngineerCoding & AlgorithmsTechnical Screen
• Choose better bank queue and describe distributionsEasy

  This question tests your ability to apply basic queueing theory to compare waiting times and your ability to reason about how distributional shape affects central tendency measures.

  LinkedInData ScientistStatistics & MathTechnical Screen
• Collect and Query Recent User ActivityMedium

  Design a scalable user activity ingestion and querying system capable of computing metrics over rolling time windows (1 minute, 1 hour, 24 hours) with deduplication and late-arriving event handling.

  LinkedInSoftware EngineerSystem DesignOnsite
• Compare heap and stack memoryMedium

  This question evaluates understanding of memory management concepts including stack versus heap allocation, object lifetimes, allocation and free behavior, access patterns, performance characteristics, and thread visibility within the Coding & Algorithms domain.

  LinkedInSoftware EngineerCoding & AlgorithmsTechnical Screen
• Compare queueing systems and common distributionsMedium

  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.

  LinkedInData ScientistStatistics & MathTechnical Screen
• Compute each member’s current notification statusEasy

  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.

  LinkedInData ScientistData Manipulation (SQL/Python)Technical Screen
• Compute graph distance and impacted servicesMedium

  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.

  LinkedInSoftware EngineerCoding & AlgorithmsOnsite
• Compute point-to-segment minimum distanceEasy

  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.

  LinkedInMachine Learning EngineerCoding & AlgorithmsTechnical Screen
• Compute total covered interval lengthMedium

  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.

  LinkedInMachine Learning EngineerCoding & AlgorithmsTechnical Screen
• Count Article Types ViewedMedium

  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.

  LinkedInData ScientistData Manipulation (SQL/Python)Technical Screen
• Count Distinct Values in a Huge Sorted ArrayMedium

  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.

  LinkedInSoftware EngineerCoding & AlgorithmsOnsite
• Count Subsequences Whose Minimum Plus Maximum Stays Within a TargetMedium

  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.

  LinkedInSoftware EngineerCoding & AlgorithmsOther
• Count connected land components in a gridMedium

  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.

  LinkedInSoftware EngineerCoding & AlgorithmsOnsite
• Count islands and distinct shapesMedium

  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.

  LinkedInSoftware EngineerCoding & AlgorithmsOnsite
• Debug Queues and Solve ArraysEasy

  Tests array traversal, sliding window techniques, and handling wrap-around logic in circular data structures with edge cases.

  LinkedInSoftware EngineerCoding & AlgorithmsOnsite
• Derive expectation for two consecutive headsMedium

  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.

  LinkedInData ScientistStatistics & MathTechnical Screen
• Derive mean and variance of x̄Medium

  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.

  LinkedInData ScientistStatistics & MathTechnical Screen
• Describe challenging teamwork and feedback handlingMedium

  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.

  LinkedInSoftware EngineerBehavioral & LeadershipOnsite
• Describe leading an infrastructure initiativeMedium

  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.

  LinkedInSoftware EngineerBehavioral & LeadershipOnsite
• Design Experiments for Email Campaign & Messaging UpdateHard

  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.

  LinkedInData ScientistAnalytics & ExperimentationOnsite
• Design Keyword Search over Posts with Exclusions and Frequency RankingMedium

  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.

  LinkedInSoftware EngineerSystem DesignOnsite
• Design LinkedIn Learning course recommendationsMedium

  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.

  LinkedInMachine Learning EngineerML System DesignOnsite
• Design O(1) Randomized MultisetEasy

  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.

  LinkedInSoftware EngineerCoding & AlgorithmsTechnical Screen