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
Machine Learning Engineer Locked

Simulate Grid Infection

This question evaluates skills in multi-source breadth-first search, synchronous simulation updates, boundary handling, and off-by-one correctness wit...

Coding & Algorithms
20
0
135 people solved
Mar 9, 2026
OpenAI logo
OpenAI
Hard
Machine Learning Engineer Locked

Schedule Incremental Labeling Tasks

This question evaluates skills in designing stateful incremental schedulers, fairness and load-balancing algorithms, deterministic tie-breaking, and e...

Coding & Algorithms
12
0
116 people solved
Apr 8, 2026
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OpenAI
Medium
Software Engineer Locked

Implement Social Follow Recommendations

This question evaluates graph data structure design and traversal, set-based aggregation and ranking logic, and the ability to justify data structure ...

Coding & Algorithms
6
0
48 people solved
May 9, 2026
OpenAI logo
OpenAI
Hard
Machine Learning Engineer

Compute time to infect all cells

You are given an n × m grid representing people in a city. - Each cell is either infected (1) or healthy (0). - Two cells are neighbors if they share ...

Coding & Algorithms
108
1
980 people solved
Oct 24, 2025
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OpenAI
Medium
Android Engineer Locked

Build a Compose Rating Card

This question evaluates proficiency in Android UI development with Kotlin and Jetpack Compose, emphasizing custom composable design (a stateless star-...

Coding & Algorithms
43
0
289 people solved
May 3, 2026
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OpenAI
Medium
Software Engineer

Generate Data Labeling Schedules

A data labeling platform manages tasks, AI models, and human annotators. Each entity has a 1-indexed string ID. You are given four integers: totalTask...

Coding & Algorithms
7
0
54 people solved
Apr 28, 2026
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OpenAI
Medium
Software Engineer

Implement toy-language types and generic substitution

Problem: Toy Language Type System (Printing + Generic Resolution) You are implementing a small type system for a custom “Toy Language”. Types can be: ...

Coding & Algorithms
72
1
1140 people solved
Nov 13, 2025
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OpenAI
Medium
Machine Learning Engineer Locked

Track Expiring GPU Credits

This question evaluates event-replay and time-window accounting skills, including temporal data structures, priority-based consumption, out-of-order e...

Coding & Algorithms
17
0
143 people solved
Mar 9, 2026
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OpenAI
Medium
Software Engineer

Design a persistent key-value store

Design and implement an in-memory key-value store with a 'medium' layer that serializes the store to bytes for persistence. Provide four functions: se...

Coding & Algorithms
35
0
431 people solved
Sep 6, 2025
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OpenAI
Hard
Software Engineer

Implement a persistent sharded key-value store

Problem Implement a simple key–value store that persists data on disk. You must store the data in fixed-size shards, where each shard is saved in one ...

Coding & Algorithms
79
1
1003 people solved
Nov 24, 2025
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OpenAI
Medium
Software Engineer

Simulate turn-based monster team battle

Design an object-oriented model and implement the core battle logic for a turn-based fight between two teams of monsters. The system should simulate t...

Coding & Algorithms
135
1
1099 people solved
Oct 30, 2025
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OpenAI
Hard
Software Engineer

Implement a Contiguous Memory Allocator with Primitive Lists

Implement a Contiguous Memory Allocator with Primitive Lists Simulate an allocator over the contiguous address range [0, capacity), initially one free...

Coding & Algorithms
1
0
14 people solved
Feb 19, 2026
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OpenAI
Hard
Software Engineer

Implement credit ledger with out-of-order timestamps

Problem You are implementing a GPU credit ledger that supports adding credits, charging credits, and querying balances. Requests can arrive in any tim...

Coding & Algorithms
140
1
950 people solved
Dec 15, 2025
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OpenAI
Medium
Backend Engineer

Convert IPv4 Ranges to CIDR Blocks

Implement a function that summarizes a consecutive IPv4 address range using the smallest possible list of CIDR blocks. You are given: - start_ip: a va...

Coding & Algorithms
6
0
106 people solved
Apr 22, 2026
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OpenAI
Medium
Software Engineer Locked

Implement an IPv4 Range Iterator

This question evaluates implementing iterative data structures and range-handling algorithms alongside numeric representation of IPv4 addresses and bi...

Coding & Algorithms
4
0
72 people solved
Jan 29, 2026
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OpenAI
Medium
Software Engineer Locked

Implement Social Graph Snapshot Queries

This question evaluates understanding of graph data structures, query-efficient indexing, and algorithmic trade-offs for static directed graphs, inclu...

Coding & Algorithms
4
0
62 people solved
Apr 13, 2026
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OpenAI
Medium
Software Engineer

Implement KV store serialization

Implement serialization and deserialization for an in‑memory key‑value store to and from a contiguous bytes buffer. Keys are UTF‑8 strings; values may...

Coding & Algorithms
106
0
824 people solved
Sep 6, 2025
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OpenAI
Medium
Software Engineer

Implement a Simulated Memory Allocator

Implement a simulated memory allocator that supports allocate(size) and free(ptr) operations analogous to malloc and free. Treat memory as a contiguou...

Coding & Algorithms
50
1
864 people solved
Sep 6, 2025
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OpenAI
Medium
Software Engineer

Implement GPU credit ledger

You manage a GPU pool with per-tenant credits. Given a list/stream of events where each event adjusts a tenant’s credit balance by a signed integer (p...

Coding & Algorithms
36
0
331 people solved
Sep 6, 2025
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OpenAI
Hard
Software Engineer

Implement Disease and Friend Snapshot Models

You are asked to solve two independent coding problems. Problem 1: Simulate disease spread on a contact graph There are n people labeled 0 through n -...

Coding & Algorithms
2
0
22 people solved
Apr 7, 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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