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
Medium
Data EngineerSenior+

Implement a stack supporting max and popMax

Design a data structure that behaves like a stack but also supports retrieving and removing the current maximum value. Implement a class MaxStack with...

Coding & Algorithms
8
0
77 people solved
Feb 2, 2026
LinkedIn logo
LinkedIn
Easy
Data Scientist

Do US members upload more videos than non-US?

You suspect video posting adoption differs between US and international members. Tables members - memberid INT (PK) - country VARCHAR (e.g., 'usa', '...

Analytics & Experimentation
8
0
76 people solved
Feb 1, 2026
LinkedIn logo
LinkedIn
Medium
Software Engineer

The Celebrity Problem

The Celebrity Problem At a party there are n people, labeled 0 to n - 1. Among them there may be exactly one celebrity — a person who satisfies both o...

Coding & Algorithms
0
0
7 people solved
Jun 23, 2026
LinkedIn logo
LinkedIn
Easy
Data Scientist

How would you lead a team to improve quality?

Behavioral / Leadership — Leading a Team to Improve Quality You are acting as a Tech Lead (TL) for a small cross-functional team (e.g., 4–8 engineers ...

Behavioral & Leadership
4
0
64 people solved
Feb 1, 2026
LinkedIn logo
LinkedIn
Medium
Software Engineer Locked

Design a meeting scheduler API

This question evaluates object-oriented design, interval data-structure and algorithmic thinking, and concurrent programming competence by requiring a...

Software Engineering Fundamentals
11
0
204 people solved
Feb 12, 2026
LinkedIn logo
LinkedIn
Medium
Machine Learning Engineer Locked

Implement alert queries and spike detection

This question evaluates a candidate's skills in streaming data structures, time-windowed aggregation, in-memory analytics for high-throughput alert in...

Coding & Algorithms
7
0
87 people solved
Feb 11, 2026
LinkedIn logo
LinkedIn
Medium
Software Engineer

Group words that map to same phone digits

Problem On a classic phone keypad (T9), letters map to digits: - 2: ABC, 3: DEF, 4: GHI, 5: JKL, - 6: MNO, 7: PQRS, 8: TUV, 9: WXYZ Given a list of lo...

Coding & Algorithms
8
0
131 people solved
Oct 20, 2025
LinkedIn logo
LinkedIn
Easy
Data Scientist Locked

How do you sample uniformly from an infinite stream?

This question evaluates understanding of streaming algorithms, randomized sampling and probability, and algorithmic space–time trade-offs involved in ...

Coding & Algorithms
13
0
128 people solved
Feb 1, 2026
LinkedIn logo
LinkedIn
Medium
Software Engineer

Design a scalable key-value store

System Design: Distributed Key-Value Store Design a distributed key-value (KV) storage service for a large-scale backend system. The service should ex...

System Design
18
0
159 people solved
Dec 8, 2025
LinkedIn logo
LinkedIn
Medium
Software Engineer

Design a Top-K search words service

Scenario Design a service that tracks user search queries and returns the Top-K most searched words/queries. Requirements Functional - API to record a...

System Design
20
0
147 people solved
Oct 20, 2025
LinkedIn logo
LinkedIn
Medium
Software Engineer

Design a company-wide monitoring system

You are asked to design a monitoring system used company-wide. Goals - Collect and query telemetry for many services/hosts - Support alerting and dash...

System Design
9
0
140 people solved
Nov 21, 2025
LinkedIn logo
LinkedIn
Easy
Data Scientist Locked

Resolve Simpson’s paradox in email A/B test

This question evaluates understanding of Simpson's paradox, causal inference, experimental design, metric selection, and statistical inference within ...

Analytics & Experimentation
10
0
94 people solved
Feb 16, 2026
LinkedIn logo
LinkedIn
Medium
Data Scientist

Implement stream random sampling in Python

You are given an unbounded stream of items that cannot be stored entirely in memory. Write Python code to maintain a uniform random sample from the st...

Coding & Algorithms
9
0
78 people solved
Oct 12, 2025
LinkedIn logo
LinkedIn
Easy
Data Scientist Locked

Handle imbalance, validate samples, and avoid overfitting

This question evaluates competencies in handling class imbalance, choosing and interpreting evaluation metrics and decision thresholds, validating sam...

Machine Learning
7
0
129 people solved
Feb 11, 2026
LinkedIn logo
LinkedIn
Medium
Software Engineer

Design scalable job scheduler and query dashboard

Design a scalable, fault-tolerant job scheduling system. The system should allow clients to schedule background jobs (for example, sending emails or r...

System Design
10
0
110 people solved
Nov 20, 2025
LinkedIn logo
LinkedIn
Easy
Data Scientist Locked

Test whether US uploads more videos

This question evaluates a data scientist's competency in observational analytics, metric definition, confounder identification and control, and statis...

Analytics & Experimentation
10
0
81 people solved
Feb 21, 2026
LinkedIn logo
LinkedIn
Hard
Data Scientist

Analyze homepage drop and feed ranking

You are interviewing for a product data science role at LinkedIn. Answer the following two product-sense questions. 1. Diagnose a drop in Home Page ->...

Analytics & Experimentation
4
0
59 people solved
Jan 17, 2026
LinkedIn logo
LinkedIn
Medium
Data EngineerSenior+

Describe a project and its impact

You are interviewing for a Staff Data Engineer role supporting information security (e.g., detection engineering, alerting, network/security infrastru...

Behavioral & Leadership
5
0
50 people solved
Feb 2, 2026
LinkedIn logo
LinkedIn
Medium
Machine Learning Engineer

Design a system for LinkedIn Skills

Design an ML system for “LinkedIn Skills”. The system should infer and/or recommend skills for members, and support downstream use cases like search/r...

ML System Design
4
0
74 people solved
Feb 18, 2026
LinkedIn logo
LinkedIn
Medium
Software EngineerSenior+ Locked

Design a metrics platform without alerting

This question evaluates a candidate's ability to design a scalable time-series metrics platform, covering data modeling for counters/gauges/histograms...

System Design
16
0
174 people solved
Dec 26, 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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