OpenAI Coding & Algorithms Interview Questions

Preparing for OpenAI Coding & Algorithms interview questions requires recognizing that OpenAI blends classic algorithmic rigor with product- and safety-oriented thinking. Interviews test algorithmic problem solving, data structures, time/space trade-offs, clean testable code, and the ability to reason about scaling, failure modes, and abuse vectors for real systems. Expect a multi-stage process—recruiter screen, one or two technical screens (pair coding or timed coding), and a final loop of 4–6 interviews covering coding, system design, deep-dives, and behavioral questions—lasting a few hours over one or two days. For interview preparation, practice medium-to-hard coding problems, timed pair-coding, system design scenarios relevant to model serving and data pipelines, and prepare concise STAR examples that highlight ownership and collaboration. Read OpenAI’s public materials and be ready to discuss trade-offs, testing, and safety considerations. Emphasize clear communication, test coverage, and justifying design choices; interviewers value well-reasoned, production-minded answers over trick solutions. Bring specific examples of shipping code and measurable impact.

90 Questions 1 Company08.01.2026
Showing 20 results
Role
OpenAI logo
OpenAI
Medium
Software Engineer

Return the Lexicographically Smallest Topological Order

Return the Lexicographically Smallest Topological Order Problem Implement topologicalOrder(nodeCount, edges) -> order. The directed graph contains nod...

Coding & Algorithms
3
0
25 people solved
Aug 1, 2026
OpenAI logo
OpenAI
Medium
Software Engineer Locked

Infection Spread Simulation with Death Threshold

This question evaluates a candidate's ability to implement grid-based simulation with multi-state cellular automaton logic, testing practical applicat...

Coding & Algorithms
10
1
63 people solved
Jun 20, 2026
OpenAI logo
OpenAI
Medium
Software Engineer Locked

Find and Count Maximum-Score Grid Paths

Find the maximum-scoring path from a fixed top-row cell to the last row of a grid using diagonal, downward, and limited two-row jump moves. Return the...

Coding & Algorithms
4
0
35 people solved
Jun 11, 2026
OpenAI logo
OpenAI
Hard
Software Engineer Locked

Consistent Hashing Ring with Virtual Nodes for Shard Rebalancing

This question evaluates a candidate's ability to design and implement a consistent hashing ring with virtual nodes for distributing keys across shards...

Coding & Algorithms
7
0
41 people solved
Jun 26, 2026
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OpenAI
Hard
Software Engineer Locked

Aggregate Recent Message Events And Active Chats

Prepare for a stateful event aggregation coding prompt over chat events and active chats in a rolling five-minute window. The question is useful for d...

Coding & Algorithms
66
1
436 people solved
Jun 5, 2026
OpenAI logo
OpenAI
Medium
Software Engineer

Count Connected Friend Groups

Count Connected Friend Groups You are given an n x n symmetric adjacency matrix. is_connected[i][j] == 1 means person i and person j are directly conn...

Coding & Algorithms
7
0
44 people solved
Jul 1, 2026
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OpenAI
Medium
Software Engineer

Implement follow graph with snapshots and recommendations

Design and implement an in-memory “social network” component that supports following/unfollowing, point-in-time (snapshot) queries, and a simple recom...

Coding & Algorithms
40
0
576 people solved
Feb 2, 2026
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OpenAI
Medium
Software Engineer Locked

Implement a Distributed Rate Limiter

This question evaluates a candidate's ability to design and implement a distributed rate-limiting mechanism, testing knowledge of distributed systems,...

Coding & Algorithms
11
0
86 people solved
May 25, 2026
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OpenAI
Medium
Software Engineer Locked

Spreading Contagion on a Grid

This question tests graph traversal and multi-source BFS on a 2D grid, evaluating a candidate's ability to model simultaneous state propagation across...

Coding & Algorithms
3
0
23 people solved
Jun 8, 2026
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OpenAI
Hard
Software Engineer Locked

Implement IP Address Arithmetic

This question evaluates proficiency in IP addressing, parsing and validation, binary/address-space arithmetic, CIDR subnet calculation, and formatting...

Coding & Algorithms
5
3
38 people solved
May 12, 2026
OpenAI logo
OpenAI
Medium
Machine Learning Engineer

Design a Resumable Iterator with Checkpoint and Restore

Design a resumable iterator: an iterator that can serialize its current position into a compact, opaque checkpoint and later be reconstructed from tha...

Coding & Algorithms
3
0
24 people solved
Oct 18, 2025
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OpenAI
Medium
Software Engineer

Implement IPv4 iterators and CIDR expansion

Problem: IPv4 Iterators and CIDR Expansion You are implementing utilities to iterate over IPv4 addresses. An IPv4 address is in dotted-decimal form: A...

Coding & Algorithms
141
0
1020 people solved
Nov 15, 2025
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OpenAI
Hard
Machine Learning Engineer Locked

Search Monster Battle Strategies

This question evaluates algorithmic problem-solving around deterministic simulation and state-space exploration, focusing on handling transient state ...

Coding & Algorithms
26
0
208 people solved
Apr 8, 2026
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OpenAI
Medium
Software Engineer Locked

Add Consecutive-Value Bonuses to Grid Paths

Extend the maximum-score grid path with bonuses for equal adjacent values and strictly increasing triples of visited cells. Dynamic programming must r...

Coding & Algorithms
1
0
20 people solved
Jun 11, 2026
OpenAI logo
OpenAI
Hard
Machine Learning Engineer Locked

Simulate Infection Spread on a Grid

This question evaluates the ability to implement and reason about discrete-time, grid-based simulations with multi-state cells and neighbor-dependent ...

Coding & Algorithms
7
0
81 people solved
May 11, 2026
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OpenAI
Hard
Software Engineer Locked

Implement a Contiguous Memory Manager

This question evaluates competence in designing efficient data structures and algorithms for interval management, contiguous allocation and deallocati...

Coding & Algorithms
10
0
151 people solved
Jan 19, 2026
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OpenAI
Easy
Software Engineer

Design a Versioned Social Follow Graph with Friend Recommendations

Design a Versioned Social Follow Graph with Friend Recommendations Build an in-memory service that maintains a directed follow graph between users and...

Coding & Algorithms
2
1
9 people solved
Mar 16, 2026
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OpenAI
Medium
Machine Learning Engineer Locked

Simulate Turn-Based Monster Battles

This question evaluates the ability to implement a turn-based battle simulation with correct state management, turn semantics, knockout handling, dama...

Coding & Algorithms
14
0
120 people solved
Mar 9, 2026
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OpenAI
Medium
Machine Learning Engineer Locked

Find Minimum Compatible Version

This question evaluates binary search, monotonic predicates, careful version ordering, and cost-aware optimization of expensive compatibility checks. ...

Coding & Algorithms
11
0
154 people solved
Mar 9, 2026
OpenAI logo
OpenAI
Hard
Software Engineer

Implement Persistent KV Store Serialization

Implement a persistent in-memory key-value store. Requirements: - Keys and values are arbitrary byte strings or UTF-8 strings; do not rely on delimite...

Coding & Algorithms
8
0
42 people solved
Apr 20, 2026

Frequently Asked Questions

How difficult are OpenAI Coding & Algorithms interview questions?
OpenAI Coding & Algorithms questions are often described as medium-to-hard in difficulty and emphasize practical engineering judgment as much as algorithmic correctness. Expect problems that require clean, testable code, attention to edge cases, and a clear discussion of time and space complexity rather than obscure puzzle tricks. Interviewers frequently push candidates to adapt solutions for production constraints, performance trade-offs, and maintainability, so preparation should cover both problem solving and engineering reasoning.
What does the typical OpenAI interview process look like, and where do Coding & Algorithms questions appear?
The usual process starts with a recruiter screen, followed by one or more technical assessments that vary by role, and culminates in final interviews that include coding, system design, and behavioral rounds. Coding and algorithms work commonly appears in the technical phone screen and in one or more live coding sessions during the final loop; some teams also use take-home exercises or pair-programming assessments. Interviewers evaluate correctness, performance, readability, and testing practices alongside communication and collaboration.
What is a sensible prep timeline to get ready for OpenAI Coding & Algorithms interviews?
A sensible timeline depends on your starting point, but many candidates follow a six- to eight-week focused plan if they have solid foundations, while those needing refreshes may take three months. Early weeks should reinforce core data structures and algorithm patterns and include timed practice in a shared editor; middle weeks should combine medium-to-hard problems with mock interviews and system-oriented algorithm questions; final weeks should emphasize code quality, testing, and rehearsing clear explanations. Recruiters often move candidates through stages in a few weeks, so align your prep with expected scheduling.
Which subtopics within Coding & Algorithms should I prioritize for OpenAI interviews?
Prioritize robust fundamentals like arrays and strings, hash maps and sets, tree and graph traversals, dynamic programming, and complexity analysis, while also practicing problems that bridge algorithms with real-world engineering such as caching, streaming, or rate-limiting logic. Equally important are writing readable, well-tested code and explaining trade-offs as you optimize. For many roles you should also be comfortable reasoning about scalability, correctness under edge cases, and how algorithmic choices affect production behavior. Practice problems that prompt you to move from a correct solution to a production-ready design.
What standout tips and common pitfalls should I know when preparing for OpenAI Coding & Algorithms interviews?
Standout tips include practicing in the same environment used by interviews, narrating your thought process clearly, writing concise tests and handling edge cases, and demonstrating trade-off reasoning when you optimize. Avoid common pitfalls like rushing to code without a plan, ignoring input validation and null cases, overfitting to toy examples, or sacrificing readability for micro-optimizations. Interviewers value pragmatic, maintainable solutions and strong communication, so balance algorithmic correctness with engineering hygiene and be ready to iterate on feedback during the session.

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