LinkedIn Interview Questions

LinkedIn Interview Questions

Practice 147 real LinkedIn interview questions for 2026. Covers all top categories — Coding & Algorithms, System Design, Analytics & Experimentation, Data Manipulation (SQL/Python), and Behavioral & Leadership — across Software Engineer, Data Scientist, Machine Learning Engineer, and Data Engineer roles. Real questions from actual interviews with detailed solutions; this collection is designed for focused interview preparation that prioritizes coding and scale-first problem solving alongside rigorous metrics thinking. Expect LinkedIn interviews to evaluate production-ready tradeoffs, clear metricization of ranking and relevance, and the ability to diagnose live-traffic regressions. For Software Engineer candidates, recurring themes include constant-time randomized data structures and frequency-weighted sampling, Top-K ranking service design and distributed-scaling considerations, plus classic array/string and stack-with-max algorithmic problems. Data Scientists should be ready for model fundamentals and optimization (logistic regression, backprop, Adam), causal and experimentation diagnostics for feed/homepage drops, and sampling/variance concerns in ranking metrics. Machine Learning Engineers will see recommendation and skills-inference system design, clustering convergence and probabilistic sampling questions, and production alerting/spike-detection. Data Engineers encounter efficient data-structure implementations tied to measurable production impact.

147 Questions 1 Company06.23.2026
Showing 20 results
Role
LinkedIn logo
LinkedIn
Easy
Data Scientist Locked

Resolve Simpson’s paradox in A/B email test

This question evaluates understanding of Simpson's paradox, causal inference, A/B testing and experimental design within the Analytics & Experimentati...

Analytics & Experimentation
3
0
51 people solved
Feb 11, 2026
LinkedIn logo
LinkedIn
Easy
Machine Learning Engineer Locked

Explain overfitting vs underfitting and fixes

This question evaluates understanding of model generalization in supervised machine learning, focusing on the concepts of overfitting and underfitting...

Machine Learning
9
0
105 people solved
Feb 8, 2026
LinkedIn logo
LinkedIn
Medium
Software Engineer

How do you win project buy-in?

Answer the following behavioral questions: 1. Describe a time when you proposed a project or technical initiative and convinced your manager and other...

Behavioral & Leadership
10
0
79 people solved
Jan 1, 2026
LinkedIn logo
LinkedIn
Easy
Data Scientist Locked

Sketch distributions and compare mean/median/mode

This question evaluates understanding of distributional shape, central tendency (mean, median, mode), skewness, outliers, and the effects of combining...

Statistics & Math
9
0
81 people solved
Feb 16, 2026
LinkedIn logo
LinkedIn
Medium
Data Scientist

Design a short-video recommendation system

Design a recommendation system for a short-video feed product. Your answer should cover the full pipeline: 1. Objective and labels: Define what the sy...

Machine Learning
5
0
96 people solved
Oct 12, 2025
LinkedIn logo
LinkedIn
Medium
Machine Learning Engineer Locked

Design a Skills inference system

This question evaluates the ability to design an end-to-end machine learning system for skills inference, including data source integration, labeling ...

ML System Design
10
0
96 people solved
Feb 11, 2026
LinkedIn logo
LinkedIn
Medium
Machine Learning Engineer Locked

Explain activations, losses, and Adam

This question evaluates understanding of neural network building blocks (layers and activation functions), comparative properties of activation/gating...

Machine Learning
15
0
130 people solved
Feb 11, 2026
LinkedIn logo
LinkedIn
Medium
Data Scientist

Derive expectation for two consecutive heads

Waiting Time Until First HH (Two Consecutive Heads) Setup Let T be the number of coin flips required until the pattern HH (two consecutive heads) appe...

Statistics & Math
7
0
87 people solved
Oct 13, 2025
LinkedIn logo
LinkedIn
Medium
Software Engineer

Explain a past project and critique a prior team

Interview prompts 1. Project deep dive: Pick a past project you worked on and walk through it end-to-end. Be ready to use a whiteboard to explain arch...

Behavioral & Leadership
10
0
114 people solved
Oct 20, 2025
LinkedIn logo
LinkedIn
Medium
Software Engineer

Find k closest values in a BST

Find k closest values in a BST Given a binary search tree with n nodes and a real target t, return k node values whose distances to t are smallest. Im...

Coding & Algorithms
5
0
101 people solved
Aug 10, 2025
LinkedIn logo
LinkedIn
Easy
Data Scientist Locked

Choose better bank queue and describe distributions

This question evaluates probabilistic reasoning and statistical intuition—queueing theory for expected waiting time and variability plus distributiona...

Statistics & Math
4
0
59 people solved
Feb 11, 2026
LinkedIn logo
LinkedIn
Medium
Software Engineer

Explain iOS ARC and avoid retain cycles

iOS Memory Management (ARC) You have 10 minutes to explain iOS memory management under ARC. Cover the following: 1. How ARC manages object lifetime (w...

Software Engineering Fundamentals
9
0
102 people solved
Feb 11, 2026
LinkedIn logo
LinkedIn
Hard
Software Engineer

Design Top K ranking system

Design Top K ranking system System Design: Real-time Top-K from a Large/Streaming Dataset Context You receive a continuous, high-volume stream of even...

System Design
18
0
154 people solved
Jul 29, 2025
LinkedIn logo
LinkedIn
Medium
Data Scientist

Decide best email variant using stratified A/B analysis

Stratified A/B Test Across Two Strata (Week/Location) You ran an email A/B test across two strata defined by week/location. Each user receives at most...

Analytics & Experimentation
7
0
73 people solved
Oct 13, 2025
LinkedIn logo
LinkedIn
Medium
Software Engineer

Design a max-stack with efficient operations

Design a max-stack with efficient operations Design a stack that supports push (x), pop(), top(), peekMax(), and popMax(). The popMax operation must r...

Coding & Algorithms
8
0
69 people solved
Aug 8, 2025
LinkedIn logo
LinkedIn
Medium
Software Engineer

Design an in-memory key-value store using maps

Design a low-level key-value store library (like an embedded storage engine) under an interview constraint: you may use only map/dictionary-like data ...

System Design
19
0
138 people solved
Nov 21, 2025
LinkedIn logo
LinkedIn
Medium
Data Scientist Locked

Derive mean and variance of x̄

This question evaluates understanding of expectation, variance, covariance structure, and how dependence between observations affects the precision of...

Statistics & Math
5
0
74 people solved
Feb 19, 2026
LinkedIn logo
LinkedIn
Medium
Machine Learning Engineer

Design LinkedIn Learning course recommendations

Design a mini ML system to recommend LinkedIn Learning courses to a user. Product goal: - Recommend courses that help the user succeed in their job se...

ML System Design
8
0
73 people solved
Feb 18, 2026
LinkedIn logo
LinkedIn
Medium
Data Scientist

Handle imbalance, sampling, and overfitting

Machine Learning Fundamentals: Imbalance, Sampling, Overfitting, and Regularization You are asked several machine learning fundamentals questions in a...

Machine Learning
7
0
55 people solved
Jul 8, 2025
LinkedIn logo
LinkedIn
Medium
Software Engineer

Differentiate Java final, finalize, finally

Differentiate Java's final, finalize, and finally. Define what final means for variables, methods, and classes and give examples; explain what finaliz...

Coding & Algorithms
8
0
72 people solved
Sep 6, 2025

Frequently Asked Questions

How difficult are LinkedIn interview questions?
LinkedIn interview difficulty varies by role and level but is generally medium-to-hard for technical roles. For software engineers expect algorithmic coding problems that are often LeetCode-medium-to-hard complexity, plus harder system design for senior levels. Data scientist and machine learning engineer rounds emphasize applied statistics, experiment design, model evaluation, and production ML system tradeoffs rather than purely theoretical proofs. Data engineer and analytics roles focus on scalable data pipelines, SQL performance, and practical ETL challenges. Interviewers expect clear thinking under time pressure, scalable designs, and strong communication; failing to justify tradeoffs or to explain assumptions is the most common failure mode.
What is the LinkedIn interview process and where do these 147 LinkedIn interview questions appear?
LinkedIn hires through a staged process starting with a recruiter screen, a technical phone screen or online assessment, then a virtual onsite loop of four to five interviews that combine coding, system or ML design, and behavioral rounds. The 147 questions in this set map across Data Scientist, Software Engineer, Machine Learning Engineer, and Data Engineer tracks: expect coding and data-structure problems in software engineering rounds, SQL and experiment/statistics problems in data science rounds, ML system and recommendation design for MLE roles, and pipeline and performance problems for data engineers. Senior candidates face heavier design and leadership evaluation.
How should I structure a preparation timeline to cover 147 LinkedIn interview questions before my onsite?
Plan a 6–10 week timeline depending on your starting level. Spend weeks 1–2 refreshing fundamentals: data structures, SQL, probability, and core ML concepts. Weeks 3–6 alternate focused practice blocks for each role represented in the 147 questions: two days of coding problems, one day of systems or modeling design, and one day of SQL/experimentation work per week. Reserve the final 1–2 weeks for timed mock interviews, behavioral STAR stories, and reviewing weak spots. Spread practice across real interview-like conditions with a shared editor for coding and a whiteboard or doc for designs.
What are the key subtopics I should prioritize across positions at LinkedIn?
Prioritize role-specific themes revealed by actual question titles: for data scientists focus on logistic regression and backprop intuition, causal experiment design, diagnosing traffic or feed relevance drops, imbalance handling, and variance reduction methods in ensembles. For software engineers prioritize efficient randomized data structures, O(1) insert/delete, top-K ranking services, common string and subarray algorithms, and debugging distributed queues. Machine learning engineers should emphasize recommender-system design, feature sampling and weighted-index sampling, K-means convergence, and practical ML pipeline monitoring. Data engineers should demonstrate robust stack implementations and measurable impact from pipeline projects.
Any standout tips and common pitfalls for LinkedIn interviews I should watch for?
Emphasize clear assumptions, measurable success metrics, and tradeoffs in every design or analysis answer. For data roles always tie model or experiment choices back to business metrics and experiment validity; avoid asserting causation without addressing confounders. For coding, prioritize correctness with clear complexity analysis and then optimize incrementally. In system and ML design, call out data pipelines, monitoring, alerting, and rollback strategies. Common pitfalls include vague requirements, skipping edge cases, ignoring scale and reliability, and weak communication; rehearse concise explanations and have two to three strong impact stories ready.

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