What are LinkedIn's hard interview questions?

Tryprepforge has 5 hard-level LinkedIn interview questions covering coding, system design, and behavioral topics. Practice with AI-powered walkthroughs and solutions.

How do I prepare for hard LinkedIn interview questions?

Start with LinkedIn's hard questions on Tryprepforge to build confidence at the right level, then progress through medium and hard questions with AI follow-up questions and step-by-step walkthroughs.

LinkedIn Hard Interview Questions

5 hard-level practice questions for LinkedIn technical interviews

Coding

All

Hard

coding Hard Verified Question #1

1. [OA] Minimum Weight Ceiling Path

Category: Graph coding problem

A network topology connects n servers labeled 1 to n. Each connection is a bidirectional link with a bandwidth cost. A network engineer needs...

Input: Graph (nodes and edges)
Output: Integer

coding Hard Verified Question #2

2. Priority Cache System

Category: String coding problem

A CDN (Content Delivery Network) maintains a fixed-capacity cache of web content. Each content item has an associated priority score. When the cache...

Input: String
Output: Integer

coding Hard Verified Question #3

3. Combine N-ary Trees

Category: Tree coding problem

You are given the roots of two N-ary organization charts, each representing a hierarchical department structure. Every node has an integer...

Input: List
Output: Computed result

coding Hard graph #1

1. [OA] Depth First Search — Find all connected components in a network of LinkedIn profiles

LinkedIn's algorithm can identify connections between users to enhance networking. We want to find all connected components given a list of connections between user profiles.
Problem statement: Given an integer n representing the number of profiles and a list of connections edges, return the connected components across profiles.
- Input: int n, edges defined as a list of pairs representing connections.
- Output: List[List[int]] — a list that contains all connected components, with each component being a list of profile IDs.

Example 1:
Input: n = 5, edges = [[0, 1], [1, 2], [3, 4]]
Output: [[0, 1, 2], [3, 4]]
Explanation: Profile 0 is connected to 1 and 2; profile 3 is connected to 4.

Example 2:
Input: n = 4, edges = [[0, 1], [1, 0], [2, 3]]
Output: [[0, 1], [2, 3]]

Constraints:
- 0 <= n <= 2000
- 0 <= edges.length <= n * (n - 1) / 2

coding Hard sliding window #2

2. [OA] Sliding Window — Implement a feature to find the longest substring without repeating characters in profile descriptions

LinkedIn users often write descriptive profiles, and analyzing these descriptions can help in improving user engagement. The goal is to identify the longest substring from a given profile description where no characters are repeated.
Problem statement: Given a string s, return the length of the longest substring without repeating characters.
- Input: string s
- Output: int — length of the longest substring without repeating characters.

Example 1:
Input: "abcabcbb"
Output: 3
Explanation: The answer is "abc", with the length of 3.

Example 2:
Input: "bbbbb"
Output: 1
Explanation: The answer is "b", with the length of 1.

Constraints:
- 0 <= s.length <= 5 * 10^4
- s consists of English letters, digits, symbols, and spaces.

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