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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 1711–1740 of 3640 results
- Lead BankMediumSoftware EngineerProcess a Mutable Stock-Price Log
Design an in-memory mutable stock price log that supports recording prices, tracking update history, calculating percentage changes across dates, and comparing performance between tickers.
Coding & AlgorithmsOnsitehash-tabledesigndata-structures - Lead BankMediumSoftware EngineerSolve friend recommendations and time-versioned maps
This problem tests your ability to model a time-versioned key-value store and leverage graph adjacency structures to perform multi-hop relationship recommendations.
Coding & AlgorithmsOnsiteBinary SearchGraphsHash Maps - LegoraMediumSoftware EngineerDeep-Dive into a Technical Project
Tests an engineer's ability to articulate, defend, and reflect on a complex technical project, demonstrating clear ownership, architectural decision-making, and self-awareness about trade-offs and failures.
Behavioral & LeadershipOnsiteSystem ArchitectureTechnical LeadershipTrade-offs - LegoraMediumSoftware EngineerDesign Direct File Uploads for a Chat Application
Design a scalable direct-to-object-store file upload pipeline for a chat platform, focusing on presigned authorization, durable lifecycle tracking, asynchronous validation, and orphan reconciliation.
System DesignOnsiteObject StorageFile UploadDistributed Systems - LegoraMediumBackend EngineerDesign a Cloud-Agnostic Upload Adapter
Design a provider-neutral object storage upload client that unifies cloud SDK behaviors while supporting streaming, multipart uploads, error normalization, and provider-specific escape hatches.
Software Engineering FundamentalsOnsiteapi-designcloud-storageobject-oriented-design - LegoraMediumSoftware EngineerDesign a Cloud-Provider Upload Adapter
Design a modular, provider-agnostic upload adapter interface that enables clients to perform direct uploads to cloud storage (e.g., S3, GCS, Azure Blob). The problem evaluates object-oriented API design, error normalization, capability negotiation, and idempotent verification workflows.
Software Engineering FundamentalsOnsiteapi-designobject-oriented-designcloud-storage - LegoraHardSite Reliability EngineerDesign a Compliance Audit Log Platform
Design an immutable, multi-tenant compliance audit logging platform that supports canonical ingestion, cryptographic tamper evidence, gap detection, and efficient legal investigation queries at scale.
System DesignOnsiteDistributed SystemsSRESecurity - LegoraMediumSoftware EngineerPresent a Technically Challenging Project
Tests a candidate's ability to communicate complex technical work, defend architectural decisions under scrutiny, and demonstrate end-to-end ownership from problem formulation to production operations.
Behavioral & LeadershipOnsiteBehavioralSystem DesignTechnical Communication - LiftoffMediumSoftware EngineerCompute the Eddington number from ride distances
This question evaluates a candidate's competence in array manipulation, ordering/selection techniques, counting thresholds, and algorithmic complexity analysis required to compute the Eddington number.
Coding & AlgorithmsOnsite - LiftoffMediumSoftware EngineerDesign and implement core Tetris game logic
This question evaluates practical implementation skills in game logic, real-time state and event management, piece rotation and movement handling, line-clearing algorithms, and clean, testable code organization.
Software Engineering FundamentalsOnsite - LiftoffMediumSoftware EngineerFind degrees of connection in a LinkedIn graph
This question evaluates understanding of graph traversal, reachability and shortest-path concepts along with the ability to manage performance constraints on large sparse graphs.
Coding & AlgorithmsOnsite - LiftoffMediumSoftware EngineerParse and expand an IPv6 address
This question evaluates proficiency in IPv6 address parsing, string validation, and canonicalization, testing understanding of hexadecimal hextets and the zero-compression (::) rule within the Coding & Algorithms domain.
Coding & AlgorithmsOnsite - LiftoffHardMachine Learning EngineerProbability That the Sum of 1,000 Fair Die Rolls Exceeds a Threshold
A fair six-sided die is rolled 1,000 times; estimate the probability that the sum of the faces exceeds a threshold, including a threshold of 600. Tests the mean and variance of one roll, how they scale for a sum of independent rolls, the normal approximation with a continuity correction, and range checks.
Statistics & MathOnsite - LilaMediumMachine Learning EngineerDebug a Transformer bug in an unfamiliar repo
This question tests your ability to identify and rectify a logical error in a Transformer's multi-head self-attention mechanism, specifically focusing on tensor dimensionality, causality masking, and numerical stability.
Software Engineering FundamentalsOnsiteTransformersDeep LearningDebugging - LilaMediumMachine Learning EngineerDesign a DNA-sequence optimization loop
This problem tests your ability to design a closed-loop active learning system for protein or DNA sequence engineering, focusing on the iterative cycle of sequence generation, uncertainty estimation, and experimental validation.
ML System DesignOnsiteActive LearningGenerative ModelsBioinformatics - LinkedInMediumMachine Learning EngineerAnswer practical ML foundations questions
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.
Machine LearningOnsite - LinkedInMediumSoftware EngineerBlock Malicious IPs at an API Gateway Across Data Centers
Design gateway IP-block enforcement with trusted client addresses, versioned rules, fast local checks, expiration, and multi-data-center propagation.
System DesignOnsite - LinkedInMediumSoftware EngineerCollect and Query Recent User Activity
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.
System DesignOnsitesystem-designdistributed-systemsstream-processing - 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 - 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 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 - 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 - 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
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