LinkedIn Interview Questions
Practice 148 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.
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"10 years of experience but never worked at a top company. PracHub's senior-level questions helped me break into FAANG at 35. Age is just a number."
"I was skeptical about the 'real questions' claim, so I put it to the test. I searched for the exact question I got grilled on at my last Meta onsite... and it was right there. Word for word."
"Got a Google recruiter call on Monday, interview on Friday. Crammed PracHub for 4 days. Passed every round. This platform is a miracle worker."
"I've used LC, Glassdoor, and random Discords. Nothing comes close to the accuracy here. The questions are actually current — that's what got me. Felt like I had a cheat sheet during the interview."
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"Legit the only resource you need. TC went from 180k -> 350k. Just memorize the top 50 for your target company and you're golden."
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"Literally just signed a $600k offer. I only had 2 weeks to prep, so I focused entirely on the company-tagged lists here. If you're targeting L5+, don't overthink it."
"Coaches and bootcamp prep courses cost around $200-300 but PracHub Premium is actually less than a Netflix subscription. And it landed me a $178K offer."
"I honestly don't know how you guys gather so many real interview questions. It's almost scary. I walked into my Amazon loop and recognized 3 out of 4 problems from your database."
"Discovered PracHub 10 days before my interview. By day 5, I stopped being nervous. By interview day, I was actually excited to show what I knew."
"I recently cleared Uber interviews (strong hire in the design round) and all the questions were present in prachub."
"The search is what sold me. I typed in a really niche DP problem I got asked last year and it actually came up, full breakdown and everything. These guys are clearly updating it constantly."
Explain overfitting vs underfitting and fixes
Question 1. What are overfitting and underfitting? 2. How can you diagnose each using training/validation metrics? 3. What are common mitigations for ...
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...
Plan and lead a large recommendation project
You are given a recommendation design problem, but the interviewer focuses on leadership and execution rather than detailed modeling. Explain how you ...
Compute graph distance and impacted services
Part A — Graph shortest distance (BFS) You are given an interface representing a node in an unweighted graph: `java interface Candidate { String id(...
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...
Implement alert queries and spike detection
You are building an in-memory alert analytics component. Each alert has: - timestamp (integer seconds since epoch) - severity (one of a small fixed se...
Check perfect square using binary search
Perfect Square Check (Binary Search) Given a positive integer n, determine whether it is a perfect square (i.e., there exists an integer x such that x...
Sample uniformly from a circle’s area
How would you generate a point (x, y) uniformly at random from the area of a circle of radius R centered at the origin? - Explain why naive choices (e...
Handle imbalance, sampling, and overfitting
Practical ML questions (classification and generalization) Answer the following ML engineering/data science questions. A) Class imbalance You’re train...
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...
Compute each member’s current notification status
You have two tables describing LinkedIn members’ push notification settings. Tables status — each member’s latest setting as of 2020-01-31 - member_id...
Design a metrics platform without alerting
Design a metrics platform (like a simplified Prometheus/Datadog metrics product) that supports collecting, storing, querying, and visualizing metrics....
Sample index from probability distribution
You are given a discrete probability distribution for an \(M\)-sided die as an array p[0..M-1], where each p[i] is non-negative. Design a function sam...
Solve six algorithmic problems
Answer the following independent algorithmic prompts. For each, explain your approach, justify data structures, analyze time/space complexity, and pro...
Compute point-to-segment minimum distance
Problem Given a 2D point P(x, y) and a line segment with endpoints A(x1, y1) and B(x2, y2), compute the minimum Euclidean distance from point P to the...
Write SQL for rankings, state, and aggregations
You are given several independent datasets. For each dataset, write the required SQL query (ANSI SQL is fine). Assume dates are in UTC and DATE column...
Count Trips From Vehicle Logs
You are given a text log of vehicle events on a road system. Each log record contains: - license_plate: a string identifying a vehicle - event_type: o...
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...
Can You Place N Objects?
You are given a binary array slots representing a row of locations. 1 means the location is already occupied, and 0 means it is empty. You want to pla...
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...