Linkedin Software Engineer Interview Questions
Practice the exact questions companies are asking right now.
Solve min window & animal conflicts
Question LeetCode 76. Minimum Window Substring: Given strings s and t, return the smallest substring of s that contains every character of t (includin...
Describe challenging teamwork and feedback handling
Behavioral Interview Prompts (Software Engineer, Onsite) Context: You are a software engineer interviewing onsite. Prepare concise answers (1–2 minute...
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 events, each referencing an item...
Reverse a linked list
Question LeetCode 206. Reverse Linked List — Given the head of a singly linked list, reverse the list and return the reversed list. https://leetcode.c...
Find lowest common ancestor
Question LeetCode 236. Lowest Common Ancestor of a Binary Tree — Given a binary tree, find the lowest common ancestor (LCA) of two given nodes. Follow...
Count islands and distinct shapes
Question LeetCode 200. Number of Islands LeetCode 694. Number of Distinct Islands https://leetcode.com/problems/number-of-islands/description/ https:/...
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(...
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....
Implement an LRU cache with follow-ups
Coding: Implement an LRU Cache and discuss concurrency Design and implement an in-memory Least Recently Used (LRU) cache data structure. The cache sho...
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...
Find the k-th largest element in an array
Given an integer array nums and an integer k, return the k-th largest element in the array. Notes: - The k-th largest element is the element that woul...
Merge two N-ary trees by key rules
You are given two N-ary trees A and B. Each node has: - key (string): unique among siblings (i.e., within a node’s children list, no two children shar...
Count connected land components in a grid
You are given a 2D grid of characters where: - '1' represents land - '0' represents water A group of land cells forms an island if they are connected ...
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 ...
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...
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...
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...
Validate parentheses with one or three bracket types
Problem Given a string s consisting only of bracket characters, determine whether it is valid. A string is valid if: - Every opening bracket has a cor...
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...
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...