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 10 results
Role
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OpenAI
Medium
Software Engineer Locked

Compute Plant Infection Stabilization

This question evaluates a candidate's ability to model and simulate discrete-time state transitions on grids, reason about propagation dynamics and ev...

Coding & Algorithms
13
0
87 people solved
Feb 17, 2026
OpenAI logo
OpenAI
Hard
Software Engineer Locked

Implement type AST and infer generics

This question evaluates a candidate's ability to design an abstract syntax tree representation and implement generic type inference for a small langua...

Coding & Algorithms
26
2
363 people solved
Feb 11, 2026
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OpenAI
Medium
Software Engineer Locked

Implement an IPv4 Iterator

This question evaluates proficiency in IPv4 address representation and arithmetic, CIDR parsing, iterator API design for forward and backward traversa...

Coding & Algorithms
4
0
47 people solved
Jan 19, 2026
OpenAI logo
OpenAI
Medium
Software Engineer

Implement delimiter-free string codec

Design an encoder/decoder for a list of strings. - Implement two functions: - encode(strings: List[str]) -> str - decode(blob: str) -> List[str] -...

Coding & Algorithms
13
0
110 people solved
Oct 31, 2025
OpenAI logo
OpenAI
Medium
Software Engineer

Design a parser for a hypothetical language

You are given a set of syntax rules for a hypothetical programming language written in BNF/EBNF. Design data structures and algorithms that: ( 1) pars...

Coding & Algorithms
50
0
424 people solved
Sep 6, 2025
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OpenAI
Medium
Software Engineer

Implement expiring credit ledger

Implement an expiring-credit ledger that supports out-of-order events. Expose three functions with the following semantics: - add_credit(id, amount, t...

Coding & Algorithms
25
0
250 people solved
Sep 6, 2025
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OpenAI
Medium
Machine Learning Engineer

Find earliest supporting version under constraints

You are given version strings formatted as {major}.{minor}.{patch}, e.g., "103.003.03". Each version either supports a feature or not. You may call is...

Coding & Algorithms
29
0
472 people solved
Sep 6, 2025
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OpenAI
Medium
Machine Learning Engineer

Find earliest supporting dependency version

Question Given a list of dependency versions (e.g. [103.003.02, 103.003.03, 203.003.02]) and a black-box API isSupported(v), design an algorithm to fi...

Coding & Algorithms
66
0
501 people solved
Aug 4, 2025
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OpenAI
Medium
Software Engineer

Merge overlapping intervals

Question LeetCode 56. Merge Intervals – Given a collection of intervals, merge all overlapping intervals into one and return an array of the non-overl...

Coding & Algorithms
23
0
218 people solved
Aug 4, 2025
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OpenAI
Hard
Machine Learning Engineer

Implement in-memory database insert and delete operations

Design and implement a simple in-memory database (key-value store) that supports the following operations: - insert(key, value): Insert a key-value pa...

Coding & Algorithms
12
0
170 people solved
Apr 6, 2025

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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