OpenAI Machine Learning Interview Questions

OpenAI Machine Learning interview questions are distinct for their emphasis on both deep machine-learning fundamentals and production-ready engineering judgment. Interviewers typically evaluate your understanding of model design and evaluation, experimental rigor, safety and ethical tradeoffs, and your ability to communicate complex decisions clearly under ambiguity. Effective interview preparation should therefore balance refreshing core theory with writing clear, performant code and practicing concise technical storytelling. OpenAI’s public interview guide outlines stages such as resume review, skills-based assessments, and multi-hour final interviews that focus on domain expertise and collaboration. ([openai.com](https://openai.com/interview-guide?utm_source=openai)) In practice you should expect a mix of hands-on coding (data pipelines, vectorized ops, debugging), model-focused questions (transformers, optimization, metrics), system-design conversations about training and deployment, and behavioral deep dives on past projects and safety considerations. Prep by rehearsing tight deep-dives of your most impactful projects, doing timed practical ML coding and debugging exercises, reviewing statistics and experimental design, and reading recent OpenAI research and blog posts so you can discuss tradeoffs confidently. Recruiters often provide role-specific prep notes and may include take-home or pair-programming assessments, so structure a timeline that alternates focused reading with hands-on practice. ([interviewquery.com](https://www.interviewquery.com/interview-guides/openai-machine-learning-engineer?utm_source=openai))

27 Questions 1 Company06.27.2026
Showing 20 results
Role
OpenAI logo
OpenAI
Medium
Machine Learning Engineer Locked

Implement Masked Cross-Entropy with Label Smoothing

Implement numerically stable masked cross-entropy in NumPy with label smoothing and optional temperature scaling. Validate shapes, dtypes, finite logi...

Machine Learning
66
1
561 people solved
Jun 27, 2026
OpenAI logo
OpenAI
Medium
Machine Learning Engineer Locked

Implement 1NN with NumPy

This question evaluates implementing a 1-nearest-neighbor classifier with NumPy, testing skills in vectorized numerical computation, distance metrics,...

Machine Learning
287
3
2722 people solved
May 19, 2026
OpenAI logo
OpenAI
Medium
Machine Learning Engineer

Compute entropy and implement 1-NN

You are given two short ML coding problems from a machine-learning engineer screen. Both are implementation-focused but probe whether you understand t...

Machine Learning
121
1
1153 people solved
Apr 24, 2026
OpenAI logo
OpenAI
Medium
Machine Learning Engineer

Derive Sharded Matrix Multiplication and Backpropagation

Derive Sharded Matrix Multiplication and Backpropagation Consider Y = X @ W, where X has shape (B, D) and W has shape (D, H). Training runs on P devic...

Machine Learning
27
0
290 people solved
Apr 19, 2026
OpenAI logo
OpenAI
Hard
Machine Learning Engineer

Improve Training With Noisy Annotators

You are given a labeled training dataset as a Pandas DataFrame. Each row contains feature columns, an observed label, and an annotator_id identifying ...

Machine Learning
90
0
782 people solved
Apr 2, 2026
OpenAI logo
OpenAI
Hard
Machine Learning Engineer

Improve classifier with noisy multi-annotator labels

Problem You are given a text dataset for a binary classification task (label in $\{0,1\\}$). Each example has been labeled by multiple human annotator...

Machine Learning
905
3
6118 people solved
Feb 11, 2026
OpenAI logo
OpenAI
Medium
Machine Learning Engineer

Debug MiniGPT and Backpropagate Matmul

This is a hands-on PyTorch screen with two independent tasks. You share a code editor with the interviewer and are expected to run the code, read trac...

Machine Learning
106
0
1062 people solved
Apr 3, 2026
OpenAI logo
OpenAI
Hard
Machine Learning Engineer

Compute Matrix Prefix Products And Gradients

You are given $N$ square matrices $A[0], A[1], \dots, A[N-1]$, each of shape $D \times D$. Define the inclusive prefix (cumulative) products: $$Y[i] =...

Machine Learning
77
0
795 people solved
Apr 2, 2026
OpenAI logo
OpenAI
Hard
Machine Learning Engineer Locked

Implement Backprop for a Tiny Network

This question evaluates understanding of backpropagation, gradient derivation, numerical stability of softmax cross-entropy, and practical implementat...

Machine Learning
175
0
1503 people solved
Apr 3, 2026
OpenAI logo
OpenAI
Medium
Machine Learning Engineer Locked

Filter Bad Human Annotations

This question evaluates expertise in data quality and annotation filtering for machine learning, including annotator reliability modeling, noisy-label...

Machine Learning
125
0
1384 people solved
Apr 3, 2026
OpenAI logo
OpenAI
Hard
Machine Learning Engineer

Derive Backpropagation for Matrix-Product Layers

Consider a neural-network block whose output is produced by multiplying a sequence of trainable weight matrices together, then applying the resulting ...

Machine Learning
51
0
594 people solved
Feb 5, 2026
OpenAI logo
OpenAI
Hard
Data Scientist

Debug and fix a PyTorch Transformer training loop

Minimal Causal LM Debugging and Optimization You are given a tiny causal decoder-only language model implemented in PyTorch. It appears to "train" but...

Machine Learning
311
0
2111 people solved
Oct 13, 2025
OpenAI logo
OpenAI
Medium
Machine Learning Engineer

Defend a Research Direction and Experiment Design

You are interviewing for a research-focused Machine Learning Engineer role at a frontier AI lab. The onsite includes a collaboration / research-discus...

Machine Learning
30
0
202 people solved
Apr 13, 2026
OpenAI logo
OpenAI
Medium
Machine Learning Engineer Locked

Debug a Broken Transformer

This question evaluates proficiency in debugging and reconfiguring Transformer-based deep learning models, covering competencies in model internals (a...

Machine Learning
103
0
810 people solved
Mar 3, 2026
OpenAI logo
OpenAI
Medium
Software Engineer

Implement and Debug Backprop in NumPy

Two-Layer Neural Network: Backpropagation and Gradient Check (NumPy) You are implementing a fully connected two-layer neural network for multi-class c...

Machine Learning
92
1
1736 people solved
Sep 6, 2025
OpenAI logo
OpenAI
Medium
Data Scientist Locked

Implement NumPy neural-network layers

This question evaluates competency in implementing neural-network layers and array algebra in NumPy, including matrix multiplication, broadcasting rul...

Machine Learning
43
0
353 people solved
Feb 18, 2026
OpenAI logo
OpenAI
Hard
Machine Learning Engineer

Debug transformer and train classifier

Debug and Fix a Transformer Text Classifier, Then Train and Evaluate It You inherit a small codebase for a transformer-based text classifier. It ships...

Machine Learning
173
0
2030 people solved
Aug 4, 2025
OpenAI logo
OpenAI
Hard
Machine Learning Engineer

Debug a broken Transformer implementation

You are given a small Transformer model implementation (e.g., in PyTorch) plus a tiny training script. The code executes, but the model does not match...

Machine Learning
171
0
1215 people solved
Jan 21, 2026
OpenAI logo
OpenAI
Medium
Machine Learning Engineer

Implement Prefix Products and Their Backward Pass

Let x[0..n-1] be a sequence and define inclusive prefix products by y[i] = x[0] x[1] ... * x[i]. Work through the following variants. State how zero...

Machine Learning
4
0
53 people solved
Aug 23, 2025
OpenAI logo
OpenAI
Hard
Machine Learning Engineer

Diagnose Transformer training and inference bugs

Debugging a Transformer That Intermittently Throws Shape/Dtype Errors and Fails to Converge You inherit a Transformer-based sequence model (decoder-on...

Machine Learning
107
0
828 people solved
Aug 11, 2025

Frequently Asked Questions

How difficult are OpenAI Machine Learning interview questions?
OpenAI Machine Learning questions are generally challenging and designed to probe both deep theoretical understanding and practical engineering ability. Expect a mix of mathematical reasoning about probabilistic models and optimization, applied questions about training and debugging large models, and coding exercises that demonstrate clean, production-ready implementations. Interviewers often evaluate your ability to reason under uncertainty, explain trade-offs, and connect empirical results to theory. While difficulty varies by level, strong candidates typically show solid fundamentals in statistics and optimization, fluency with deep learning architectures, and clear, concise communication about experiments and outcomes.
What does the OpenAI interview process look like for Machine Learning roles, and where will ML questions appear?
The process commonly begins with a résumé screen and a recruiter call, followed by a skills-based assessment that may be a take-home project, paired coding, or targeted technical test. If you advance, a final loop of interviews—often totaling several hours over one or two days—focuses on domain expertise. Machine learning topics appear throughout: coding rounds test implementation and debugging, technical deep dives probe your prior ML projects and experimental design, and specialised interviews assess modeling, systems for training and deployment, and safety or alignment thinking. You should also expect behavioral conversations about collaboration and impact.
How should I structure my interview preparation timeline for Machine Learning roles at OpenAI?
Begin by auditing your strengths and gaps, then build a structured plan over several weeks. Early weeks should polish your résumé and craft clear project narratives, including metrics and lessons learned. Concurrently refresh core math and ML fundamentals: probability, optimization, and model evaluation. Mid-plan focus on hands-on practice: implement models, run experiments, and rehearse coding problems that emphasize correctness and readability. Later weeks should include system-design and training-scale scenarios, mock deep dives on past work, and short practice interviews to tighten explanations. Leave final days for targeted review, restful preparation, and aligning answers to the role’s priorities.
What key Machine Learning subtopics should I master for OpenAI interviews?
Master the fundamentals: probability, statistics, and optimization techniques that underlie model training and evaluation. Be fluent with deep learning building blocks—backpropagation, regularization, and modern architectures such as transformers—and understand their inductive biases and failure modes. Know experimental design and reproducibility, metrics and evaluation strategies, and techniques for diagnosing and mitigating distribution shift and bias. At scale, be comfortable discussing data pipelines, distributed training, and inference performance trade-offs. Finally, be prepared to reason about robustness, safety, and the societal impacts of models in clear, technically grounded terms.
What standout tips improve performance on OpenAI Machine Learning interviews, and what common pitfalls should I avoid?
Standout preparation includes clear, quantitative project narratives: state the problem, approach, metrics, and specific contributions. Practice articulating trade-offs and failure analyses rather than just successes. In coding and design rounds, write readable, well-tested code and communicate your thought process. Familiarize yourself with recent ML research relevant to the role and be ready to discuss ethical or safety considerations. Common pitfalls are vague or overstated claims about results, neglecting baseline comparisons, poor experimental rigor, and failing to ask clarifying questions. Strong interviewers value curiosity, humility, and precise, reproducible thinking.

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