Pinterest Coding & Algorithms Interview Questions

Pinterest Coding & Algorithms interview questions focus on algorithmic problem solving, clear code, and pragmatic optimization. Expect an initial recruiter screen and often an online assessment (CodeSignal/LeetCode-style) before a virtual loop of 3–6 interviews that typically include timed coding rounds, follow-ups that probe complexity and edge cases, and domain-focused conversations. What’s distinctive is a balance between pure algorithms and product-aware engineering: interviewers evaluate your data-structure fluency (arrays, strings, trees, graphs, DP), runtime/space trade-offs, test-case thinking, and the ability to explain decisions clearly while iterating on solutions. For effective interview preparation, practice medium-to-hard LeetCode problems under time pressure, rehearse thinking aloud and writing clean, testable code on a shared editor, and simulate follow-ups where you optimize or generalize your solution. Reinforce complexity analysis and common pitfalls (off-by-one, NULL/edge cases, uninitialized state). Finally, prepare concise project stories that show impact and system thinking so you can connect algorithmic choices to real product constraints—this combination of technical rigor and product awareness is how candidates stand out.

66 Questions 1 Company08.02.2026
Showing 20 results
Role
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Pinterest
Hard
Software Engineer

Maintain an Escape-Room Leaderboard

Design and implement an EscapeRoomGame for a fixed set of players and rooms 0 through R. - advance(player_id) moves that player forward by one room in...

Coding & Algorithms
1
0
16 people solved
Aug 2, 2026
Pinterest logo
Pinterest
Medium
Software Engineer

Rebalance Experiment Buckets with Minimal Reassignment

Rebalance Experiment Buckets with Minimal Reassignment Problem Implement rebalanceBuckets(bucketCount, groups, targetPercentages) -> rebalancedGroups....

Coding & Algorithms
0
0
14 people solved
Jul 23, 2026
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Pinterest
Medium
Software Engineer

Select the Nearest Eligible Elevator

Select the Nearest Eligible Elevator You are given a list of elevators. Each elevator has a current integer floor and a state: "up", "down", or "idle"...

Coding & Algorithms
14
0
103 people solved
May 12, 2026
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Pinterest
Medium
Software Engineer

List Unallocated Experiment Buckets

List Unallocated Experiment Buckets Problem An experiment system divides traffic into numbered buckets. Implement findUnallocatedBuckets(bucketCount, ...

Coding & Algorithms
1
0
11 people solved
Jul 23, 2026
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Pinterest
Medium
Software Engineer

Collect Pins from Reachable Boards

Collect Pins from Reachable Boards The interview report names a board-and-pin coding problem whose intended approach was breadth-first search but does...

Coding & Algorithms
1
0
19 people solved
Jul 2, 2026
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Pinterest
Medium
Software Engineer

Settle debts with minimal transactions

You are given a list of debts among a set of people, expressed as triples (debtor, creditor, amount) (equivalently (payer, payee, amount)), where each...

Coding & Algorithms
39
0
404 people solved
Sep 6, 2025
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Pinterest
Medium
Software Engineer

Reconstruct itinerary with lexicographic ties

You are given m airline tickets as directed pairs [from, to]. Build an itinerary that starts at a specified airport start (e.g., "JFK") and uses every...

Coding & Algorithms
23
0
234 people solved
Sep 6, 2025
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Pinterest
Hard
Machine Learning Engineer

Implement a Stateful Search Autocomplete Session

Implement a Stateful Search Autocomplete Session Build an autocomplete engine from historical sentences and their usage counts. While a user types a s...

Coding & Algorithms
2
0
34 people solved
Jul 3, 2026
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Pinterest
Medium
Software Engineer

Mark and Compact a Heap-Indexed Subtree

Mark and Compact a Heap-Indexed Subtree An interview report describes an array-encoded tree, marking a target and its descendants with -1, then moving...

Coding & Algorithms
1
0
22 people solved
Jul 2, 2026
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Pinterest
Medium
Machine Learning Engineer Locked

First Word Matching Each Prefix Query

This question evaluates a candidate's grasp of string data structures and efficient prefix-matching techniques, core competencies in coding and algori...

Coding & Algorithms
1
0
13 people solved
Jun 3, 2026
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Pinterest
Hard
Machine Learning Engineer

Solve a 9x9 Sudoku puzzle

Given a partially filled 9×9 Sudoku board, fill the empty cells so that the completed board is valid. A valid Sudoku satisfies: - Each row contains di...

Coding & Algorithms
18
1
140 people solved
Dec 13, 2025
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Pinterest
Medium
Software Engineer Locked

Maximize Boxes Stored Through One Entrance

This question evaluates array manipulation, constraint reasoning, and optimization skills, touching on greedy and combinatorial allocation concepts un...

Coding & Algorithms
2
0
28 people solved
May 19, 2026
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Pinterest
Medium
Machine Learning Engineer Locked

Solve five hard algorithm problems

This set of problems evaluates algorithm design and problem-solving skills across array manipulation, range-update techniques, load-balancing and part...

Coding & Algorithms
6
0
87 people solved
Mar 8, 2026
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Pinterest
Medium
Software EngineerSenior+

Settle Group Expenses with Transfers

You are given a list of group expense transactions from a trip. Each transaction contains: - payer: the person who paid the full amount. - amount: the...

Coding & Algorithms
2
0
17 people solved
Jan 5, 2026
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Pinterest
Hard
Machine Learning Engineer Locked

Sample a string by real-valued scores

This question evaluates probabilistic sampling, numerical stability, and algorithmic implementation skills for weighted selection under floating-point...

Coding & Algorithms
12
0
138 people solved
Mar 1, 2026
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Pinterest
Medium
Software Engineer

Design a violation log analyzer

You are given an append-only list of violation events as tuples (id: string, policy: string, date: ISO-8601 string). Build an in-memory "Violation Log...

Coding & Algorithms
41
0
281 people solved
Sep 6, 2025
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Pinterest
Medium
Software Engineer

Determine equality of arbitrarily nested sets

Implement a function that determines whether two arbitrarily nested sets are equal. Sets are unordered and contain no duplicates; elements can be inte...

Coding & Algorithms
15
0
139 people solved
Sep 6, 2025
Pinterest logo
Pinterest
Medium
Software Engineer

Solve set equality and ad log top‑K

Problem Set (Coding) 1) Check whether two sets are equal You are given two integer arrays A and B that represent sets, except they may contain duplica...

Coding & Algorithms
19
0
198 people solved
Nov 11, 2025
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Pinterest
Easy
Data Scientist Locked

Implement np.random.choice

This question evaluates understanding of random sampling algorithms, probability distributions (uniform and weighted), handling of weights and edge-ca...

Coding & Algorithms
5
0
47 people solved
Feb 1, 2026
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Pinterest
Hard
Machine Learning EngineerSenior+ Locked

Support room moves and query top-k fastest

This question evaluates understanding of dynamic data structure design and ordering semantics, specifically maintaining per-room FIFO arrival order, c...

Coding & Algorithms
9
0
68 people solved
Jan 12, 2026

Frequently Asked Questions

How difficult are Pinterest Coding & Algorithms interview questions for software roles?
Pinterest Coding & Algorithms problems are typically in the medium-to-hard range for software engineering roles and often resemble LeetCode-style algorithmic challenges. Interviewers evaluate algorithmic thinking, correctness, efficiency, and code clarity rather than obscure trivia. Expect questions that require working through edge cases, explaining time and space complexity, and iterating from a brute-force idea to an optimized solution. Difficulty can vary by level; entry-level roles skew easier while senior roles demand algorithmic fluency plus design tradeoffs. Practicing timed problem-solving and clear verbalization of thought process will substantially reduce the perceived difficulty.
What is the interview process at Pinterest and where do Coding & Algorithms questions typically appear?
Pinterest’s technical hiring process normally begins with a recruiter call, followed by one or more technical screens and then an onsite or virtual interview loop. Coding & Algorithms questions commonly appear in the initial technical phone or online screen and again in the onsite loop as dedicated data-structures/algorithms interviews. Domain-specific or system-design interviews may also include algorithmic subproblems. For specialized engineering tracks, coding tasks can appear in take-home assessments or in role-specific rounds. Across stages, interviewers expect clear problem decomposition, correct implementation, and complexity analysis.
How should I structure my preparation timeline for Pinterest Coding & Algorithms interviews?
A focused preparation timeline of six to ten weeks often works well: start with fundamentals, then move to timed practice and mock interviews. Early weeks should reinforce core data structures and algorithm patterns, followed by practicing medium-to-hard problems under time pressure. In the middle of the timeline, incorporate mock interviews with feedback and review common pitfalls you encounter. In the final one to two weeks, prioritize breadth by revisiting weak topics, practicing end-to-end problem explanations, and rehearsing concise complexity analysis. Throughout, balance coding practice with clear verbalization and writing clean, testable code.
Which key subtopics in Coding & Algorithms should I prioritize for Pinterest interviews?
Prioritize core data structures and algorithmic patterns that frequently appear in interviews: arrays and strings, hashing, two-pointers and sliding windows, stacks and queues, trees and binary search trees, graphs with BFS/DFS, dynamic programming, and sorting/searching techniques. Also focus on complexity analysis, tradeoffs between time and space, handling nulls and edge cases, and implementing robust test cases. For performance-sensitive questions, have an intuition for runtime bottlenecks and basic optimizations. Practicing these subtopics in a variety of problem shapes builds the pattern recognition interviewers value.
What standout tips and common pitfalls should I know when preparing for Pinterest Coding & Algorithms interviews?
Standout preparation tips include explicitly clarifying constraints and inputs before coding, narrating your problem-solving steps, and writing correct, well-indented code with simple test cases. Start with a clear brute-force approach, then refine it while explaining tradeoffs in time and space. Common pitfalls are rushing to code without a plan, ignoring edge cases or integer overflows, and failing to justify algorithmic choices. For senior roles, avoid over-optimizing prematurely; instead demonstrate principled tradeoffs. Finally, solicit brief feedback when stuck and use small examples to validate your approach before submitting code.

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