OpenAI Interview Questions

OpenAI Interview Questions

Practice 274 real OpenAI interview questions for 2026 — real interview questions drawn from actual interviews with detailed solutions. OpenAI interview questions on this page span Coding & Algorithms, System Design, ML System Design, Machine Learning, and Data Manipulation (SQL/Python) and cover roles like Software Engineer, Machine Learning Engineer, Data Scientist, Android Engineer, and Frontend Engineer. For interview preparation expect a focus on production ML systems, scalable services, numerical correctness, experimental design, and communication: interviewers evaluate architecture decisions, tradeoffs, measurable impact, and the ability to ship robust systems under uncertainty. The loop runs stage-by-stage: a recruiter screen, a technical phone screen (coding or design), a virtual onsite with focused rounds (practical coding, system and ML design, model/debug deep dives, and behavioral/mission-fit), then team match and offer; typical timeline is about 4–8 weeks and difficulty is high. Practical coding leans toward real-world engineering problems rather than pure LeetCode puzzles. Software-engineer themes include consistent-hashing sharding, GPU job scheduling for text-to-video, payment systems with exactly-once semantics, and video orchestration. ML tracks emphasize resumable iterators and checkpoint/restore, streaming-entropy numerical stability, 1-NN implementations and debugging model backprop; data science focuses on churn, free-trial A/B tests, and SQL retention analysis. Use project deep-dives and worked examples when you prep.

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

Design a Conversational AI Assistant

This question evaluates system design, distributed systems, and real-time inference-serving competencies for building large-scale conversational AI pr...

System Design
22
0
194 people solved
Jan 29, 2026
OpenAI logo
OpenAI
Medium
Software Engineer Locked

Design a Hosted Notebook Platform

This question evaluates system design skills around stateful compute orchestration, including control-plane versus data-plane separation, workspace li...

System Design
293
0
3152 people solved
Apr 12, 2026
OpenAI logo
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
153 people solved
Mar 9, 2026
OpenAI logo
OpenAI
Medium
Software Engineer Locked

Design a Multi-Tenant Online IDE

This question evaluates system design skills for multi-tenant platform architecture, specifically assessing competency in tenancy isolation, identity ...

System Design
14
0
275 people solved
Apr 11, 2026
OpenAI logo
OpenAI
Hard
Software Engineer

Design a multi-tenant Slack-like messenger

System Design: Multi‑Tenant B2B Team Messaging (Slack‑like) Design a multi‑tenant, enterprise‑grade team messaging platform similar to Slack. Function...

System Design
8
0
170 people solved
Sep 6, 2025
OpenAI logo
OpenAI
Medium
Software Engineer

Parse and build binary data in Python

Using provided interfaces ByteReader(read(n), read_uint32_le, read_string) and ByteWriter(write(b), write_uint32_le, write_string), implement function...

Data Manipulation (SQL/Python)
18
1
159 people solved
Sep 6, 2025
OpenAI logo
OpenAI
Hard
Data Scientist

Write SQL for repeat churn

Write a SQL query to measure the performance of a free-month promotion experiment. Assume experiment_users already contains only users who were eligib...

Data Manipulation (SQL/Python)
36
0
344 people solved
Feb 3, 2026
OpenAI logo
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
39
0
562 people solved
Feb 2, 2026
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OpenAI
Hard
Data Scientist Locked

Measure free-month promotion impact

This question evaluates causal inference and experimentation skills, including randomized design and estimand framing, metric and ROI attribution, han...

Analytics & Experimentation
15
0
134 people solved
Jan 15, 2026
OpenAI logo
OpenAI
Hard
Software Engineer Locked

Design a payment system with holds and batching

This question evaluates a candidate's competency in designing reliable, auditable payment workflows, covering authorization holds, batch settlement, i...

System Design
101
0
1049 people solved
Mar 1, 2026
OpenAI logo
OpenAI
Hard
Machine Learning Engineer

Design an in-memory database

Design an in-memory database System Design: In-Memory Key–Value Database for Ultra–Low Latency Context You are designing an in-memory, per-node key–va...

System Design
22
0
152 people solved
Jul 15, 2025
OpenAI logo
OpenAI
Medium
Machine Learning Engineer

Derive MLE and Bayesian posterior for Bernoulli

Bernoulli/Binomial Inference Task You observe n independent Bernoulli trials with unknown success probability p, and you record k successes (so K ~ Bi...

Statistics & Math
57
0
507 people solved
Aug 11, 2025
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
7
0
40 people solved
Apr 20, 2026
OpenAI logo
OpenAI
Medium
Software Engineer

Debug a Machine Learning Pipeline

Debugging a Sudden Accuracy Drop in a Deployed ML Pipeline Context You are on-call for a production machine learning service. Monitoring alerts show t...

Machine Learning
51
0
672 people solved
Aug 4, 2025
OpenAI logo
OpenAI
Hard
Machine Learning Engineer

Design an AWS fine-tuning platform for LLMs

Scenario You need to build a system that lets customers fine-tune their own large language model (LLM) on AWS. Task Design a managed platform where us...

ML System Design
17
0
136 people solved
Dec 15, 2025
OpenAI logo
OpenAI
Easy
Data Scientist

Compute signup rate and retention from raw logs

Scenario You are analyzing an A/B test for a marketing campaign offering a free 1-month trial. You are given raw “upstream” tables that resemble produ...

Data Manipulation (SQL/Python)
3
0
33 people solved
Oct 4, 2025
OpenAI logo
OpenAI
Hard
Software Engineer

Design a GPT chat UI with snapshots and sharing

System Design: End-to-End Web App for Interacting with a GPT-like Model Context You are designing a multi-tenant, browser-based SaaS application that ...

System Design
16
0
202 people solved
Sep 6, 2025
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OpenAI
Hard
Machine Learning Engineer

Train a classifier and analyze dataset

End-to-End Binary Classifier Workflow (EDA → Modeling → Fairness → Report) You are given a labeled tabular dataset and asked to implement a reproducib...

Machine Learning
64
0
781 people solved
Sep 6, 2025
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OpenAI
Medium
Data Scientist

How would you evaluate a free-trial A/B test?

You run an online marketing experiment to evaluate whether offering a free 1‑month trial increases growth. Experiment context - Eligible visitors are ...

Analytics & Experimentation
9
0
178 people solved
Oct 8, 2025
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OpenAI
Hard
Data Scientist Locked

Handle repeated churn in SQL

This question evaluates proficiency in time-based data manipulation and analytics, including handling repeated churn and resubscription, interval logi...

Data Manipulation (SQL/Python)
14
0
117 people solved
Jan 22, 2026

Frequently Asked Questions

How difficult are OpenAI interview questions for software and ML roles in 2026?
OpenAI interviews in 2026 are challenging but not purely puzzle-driven: they reward practical engineering, systems thinking, and domain depth. Expect coding rounds that favor real-world tasks (reading and modifying components, debugging, performance-minded implementations) over contrived LeetCode riddles, plus heavy system and ML design for senior roles. Difficulty varies by track: Software Engineer interviews emphasize scalable distributed systems and orchestration; Machine Learning and Research tracks dig deeper into math, experiment design, and paper-level reasoning. Overall the loop is selective; prepare for multi-hour virtual onsites and high bar on correctness, clarity, and tradeoff justification.
What is the OpenAI interview process stage by stage and where do different question types appear?
The process typically starts with a recruiter or sourcer screen (30 minutes) covering fit and logistics, then a technical phone screen or hiring manager call that mixes coding and role-specific questions. Many loops include a paid or take-home exercise in applied roles, then a virtual onsite of four to six rounds: coding/debugging, system or ML systems design, a technical deep dive on your past work, and behavioral/mission-alignment conversations, followed by team-match interviews. Coding and Algorithms and Data Manipulation show up in early screens and onsite coding rounds; System Design and ML System Design dominate senior SWE and MLE rounds; Data Scientist rounds focus more on SQL, experiments, and A/B analysis.
How should I schedule my preparation and what timeline is realistic before interviewing at OpenAI?
Plan a 4–8 week preparation block aligned to the role. Weeks 1–2: solidify fundamentals—data structures, Python or chosen language fluency, and SQL skills with joins, windows, and CTEs. Weeks 3–4: practice role-specific system problems and ML fundamentals—distributed systems, caching, consistency, and experiment design. Weeks 5–6: run mock onsites, do timed coding, and prepare technical deep dives (projects, papers, metrics). Final 1–2 weeks: polish behavioral stories, team-fit pitch, and revisit tricky system/ML topics like checkpointing, numerical stability, and orchestration. Allow extra time if you must rebuild ML coding from scratch or reproduce papers.
What specific subtopics and problem types recur for OpenAI roles (coding, system design, ML, and data)?
For Software Engineers expect distributed-systems themes such as consistent hashing rings with virtual nodes, GPU job schedulers for text-to-video workloads, exactly-once payment processing, versioned social follow graphs, and video generation orchestration. Machine Learning Engineers see resumable iterators with checkpoint/restore, streaming entropy and numerical stability, 1-NN implementations and matrix gradient tricks, debugging MiniGPT-style training, mining novel images, and noisy-annotator strategies. Data Scientists focus on SQL for repeat churn, free-month promotion A/B tests, signup/retention lift calculations, and experiment measurement. Mobile and frontend roles weight architecture (MVVM, Compose) and model-usage quotas.
What are standout preparation tips and common pitfalls to avoid for OpenAI interviews?
Emphasize production-ready thinking: write clear, testable code, explain failure modes, and design for observability and reproducibility. For ML/research tracks, be ready to discuss papers, experimental design, statistical power, and how you'd debug and reproduce training runs. Avoid over-optimizing for abstract puzzle tactics; interviewers want debugging instincts, tradeoff reasoning, and a path to shipable systems. Common pitfalls include ignoring edge cases (concurrency, exactly-once semantics), skimming data-quality implications in experiments, failing to justify metric choices, and not framing past work in terms of tradeoffs and measurable impact during technical deep dives and team-match conversations.

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