LinkedIn Coding Interview Questions
32 LinkedIn coding interview problems with full optimal solutions — 4 easy, 21 medium, 7 hard. Every problem ships with multiple approaches (brute-force first, then the optimal), complexity tables for each, company-specific tips on what an LinkedIn interviewer values, and a FAQ section.
Showing 7 problems of 32
- #128hardfoundational
128. Longest Consecutive Sequence
Find the length of the longest run of consecutive integers in an unsorted array in O(n) time — LinkedIn uses this problem to check whether you can design set-based O(n) algorithms, the same reasoning they apply to detecting unbroken skill-progression sequences in member credential timelines.
- #295hardfoundational
295. Find Median from Data Stream
Design a data structure that computes the median of an ever-growing stream using two heaps — LinkedIn runs this pattern to rank feed items by engagement score in real time, where you need a running median without resorting the entire dataset on every new signal.
- #68hardcompany favorite
68. Text Justification
Given an array of words and a max line width, fully justify each line (with the last line left-aligned). LinkedIn asks this for the hard slot because it's the canonical 'simulate carefully' problem — no clever algorithm, just precise spacing distribution.
4 free resourcesSolve → - #76hardfrequently asked
76. Minimum Window Substring
Given strings s and t, return the smallest substring of s that contains every character of t (with multiplicity). LinkedIn asks this on senior loops because the canonical sliding-window template is small to write but easy to break on duplicates.
4 free resourcesSolve → - #126hardfrequently asked
126. Word Ladder II
Given begin and end words and a dictionary, return ALL shortest transformation sequences. LinkedIn asks this for the hardest BFS slot — the trick is to do BFS for distances first, then DFS to reconstruct paths only following shorter-distance neighbors.
4 free resourcesSolve → - #127hardfrequently asked
127. Word Ladder
Given begin and end words and a dictionary, return the length of the shortest transformation sequence where each step changes one letter and produces a dictionary word. LinkedIn asks this on the BFS round — they want the wildcard-bucket preprocessing trick for O(N * L^2).
4 free resourcesSolve → - #297hardfrequently asked
297. Serialize and Deserialize Binary Tree
Design an algorithm that serializes a binary tree to a string and back. LinkedIn asks this on senior loops because the preorder-with-nulls + queue-based recursive parse is the cleanest pair you can write under interview pressure.
4 free resourcesSolve →
Related interview-prep guides
HackerRank Tech Interview Guide 2026: What It Tests, How It Tracks You, and the Modern Setup
HackerRank is still the volume leader in first-round technical screens for 2026 tech hiring. A browser-sandboxed coding environment that logs every keystroke, paste event, and tab-focus change inside its own tab. This guide covers what it tests, the boundary of what it can and cannot detect, and how a modern desktop setup pairs with a HackerRank session without leaking into the screen-share.
Karat Technical Interview Guide 2026: How the Third-Party Loop Actually Works
Karat is technical-interview-as-a-service. Karat-employed engineers run the technical loop for the hiring company in Karat's own recorded video and coding environment. The dynamic is different from an in-house interview: the interviewer is a contractor, not a future teammate, the rubric is fixed, the session is recorded for asynchronous review, and the hiring team's engineers watch the playback a day later. This guide is the practical map of how that loop works in 2026 and how a modern desktop setup runs alongside it.
Microsoft Teams for Tech Interviews in 2026: The Complete Candidate Guide
Microsoft Teams is the default interview surface at any company running Office 365: Fortune 500, finance, healthcare, government tech, legacy enterprise. The recording-and-transcript reality changes the threat model versus Zoom, but the OS-level boundary that protects a modern desktop AI setup is the same. This is the candidate-side guide to running a Teams interview in 2026.