Collecting OpenAI Interview Questions - 2025 Edition: Share Your Experience

Collecting OpenAI Interview Questions - 2025 Edition :brain:

Let’s crowdsource our collective knowledge about OpenAI’s interview process


Why This Matters

OpenAI is scaling rapidly (projected $12.7B revenue, aiming for 1B users) and is one of the most competitive interview processes in tech. With median total compensation around $875K (40-50% higher than Google/Meta), it’s worth understanding their process.


What We Know So Far (2025)

Interview Structure

  • Duration: 4-6 hours across 1-2 days
  • People: 4-6 different team members
  • Experience rating: 36.1% positive (3.17/5 difficulty)
  • Timeline: Average 30.36 days, can be 6-8 weeks total

Process Breakdown

  1. Recruiter Screen (30-45 min) - Resume walkthrough, OpenAI research familiarity
  2. Technical Assessment - Pair coding, take-home, or HackerRank
  3. Technical Interviews - Practical algorithms (not pure LeetCode)
  4. Final Onsite/Virtual - The marathon round

Common Question Categories

:fire: Most Common: LRU Cache Implementation

“Solve the LRU cache problem” is THE most frequent coding question for SWE candidates.

Why it matters:

  • Tests data structures (hashmap + doubly linked list)
  • O(1) get/put operations
  • Real-world caching scenarios
  • Code quality and optimization

System Design Questions

  • “Design ChatGPT” (obviously)
  • “Design an LLM-powered enterprise search system”
  • “Design GitHub Actions from scratch”
  • “Design Yelp/Twitter/notification system”

Evaluation criteria:

  • Scalability (horizontal scaling, sharding, load balancing)
  • Reliability & fault tolerance
  • Performance (latency for real-time responses)
  • AI Infrastructure knowledge (GPU/TPU usage, distributed training, model versioning)

ML Engineering Specifics

  • Model architectures and training methodologies
  • Gradient descent optimization
  • Recent research papers in your domain
  • Data preprocessing pipelines
  • Feature engineering challenges
  • Model deployment considerations
  • Reinforcement Learning from Human Feedback (RLHF)

Mission Alignment & Ethics

  • “Why OpenAI?” - Show understanding of their mission
  • AI safety and alignment research
  • Responsible deployment approaches
  • Ethics in AI development

Sample Questions from the Wild

Coding

# Classic LRU Cache with twist
class LRUCache:
    def __init__(self, capacity: int):
        # Implement with OrderedDict or custom doubly linked list
        pass
    
    def get(self, key: int) -> int:
        # O(1) retrieval + move to front
        pass
    
    def put(self, key: int, value: int) -> None:
        # O(1) insertion + eviction if needed
        pass

System Design

  • “How would you scale ChatGPT to handle 100M concurrent users?”
  • “Design a system for real-time model A/B testing”
  • “Implement GPU credit transactions for API usage”

ML Engineering

  • “Walk through an experiment you designed to test a hypothesis”
  • “How would you improve factuality in language models?”
  • “Explain your approach to distributed training synchronization”

Preparation Strategy

Technical

  • Master LRU Cache - Multiple implementations (OrderedDict, custom linked list)
  • System design fundamentals - Focus on ML infrastructure
  • Read OpenAI’s blog and research papers
  • Understand RLHF, alignment research, safety interventions

Behavioral

  • Know their charter and mission
  • Have opinions on AI ethics and safety
  • Prepare examples of real-world problem-solving
  • Show genuine interest in responsible AI development

The Meta-Question

“OpenAI questions focus on deep reasoning, real-world problem-solving, and mission alignment—not trick questions or puzzles.”


What We Need from YOU :folded_hands:

Have you interviewed at OpenAI recently? Please share:

  1. Role you interviewed for (SWE, MLE, Research Scientist, etc.)
  2. Specific questions you remember
  3. What surprised you about the process?
  4. Preparation tips that actually helped
  5. Red flags or gotchas to avoid

Interviewing soon? Let us know:

  • What role?
  • What are you most worried about?
  • How can we help you prepare?

Even if you didn’t get the offer, your experience helps everyone. This is a judgment-free zone for sharing intel.


Recent Updates (Sept 2025)

  • Research focus shifting toward o3/o4-mini models, agentic systems (Deep Research, Operator)
  • Safety emphasis increasing - more questions about alignment and responsible deployment
  • Infrastructure scaling - questions about handling billion-user scale
  • Product integration - ChatGPT, DALL-E, API ecosystem knowledge valued

Ground Rules

:white_check_mark: Share specific questions and experiences
:white_check_mark: Help others prepare with tips and resources
:white_check_mark: Discuss interview process and timeline
:white_check_mark: Ask for help with specific preparation areas

:cross_mark: Don’t share internal/confidential information
:cross_mark: Don’t disparage anyone who didn’t get offers
:cross_mark: No self-promotion or recruiting


Let’s build the most comprehensive OpenAI interview resource on the internet. Who’s going first? :rocket:

Updated: September 2025 | Sources: Glassdoor, InterviewQuery, IGotAnOffer, OpenAI Blog

I interviewed for SWE in August 2025! Got the LRU Cache question as expected, but with a twist - they wanted me to add TTL (time-to-live) functionality. The interviewer was really focused on code quality and asked me to write comprehensive tests. Also got asked to implement GPU credit transactions with atomic operations. System design was ‘Design a real-time model A/B testing platform.’ Prep tip: they care way more about clean, production-ready code than just getting it working.

ML Engineer interview here (July 2025). They deep-dived into my experience with distributed training - specifically asked about gradient synchronization strategies and handling stragglers in parameter servers. Got a question about designing an experiment to reduce hallucinations in chat models. Also: ‘How would you implement RLHF from scratch?’ They wanted me to walk through the entire pipeline from human feedback collection to reward model training. The mission alignment questions were intense - be ready to discuss AI safety trade-offs in detail.

The Complete Guide to OpenAI Interview Questions and Process

Landing a role at OpenAI, one of the world’s leading artificial intelligence research organizations, is a dream for many software engineers. But what does the interview process actually look like? Based on insights from engineers who’ve been through it, here’s everything you need to know to prepare for your OpenAI interview.

The Reality: Expect Flexibility (and Some Chaos)

Before diving into the specifics, it’s important to understand that OpenAI’s hiring process is notably decentralized. Unlike companies with rigid, standardized interview loops, OpenAI’s process varies significantly depending on the role, team, and even timing. Candidates have reported experiencing some organizational chaos, including periods of radio silence and last-minute changes.

The entire process typically takes 6-8 weeks, though you can potentially accelerate this by maintaining pressure throughout, especially if you have competing offers.

The Four-Step Process

Step 1: The Recruiter Call (30 Minutes)

This initial conversation is fairly standard but crucial for setting expectations. Your recruiter will explore:

  • Your previous experience and technical background
  • Why you’re interested in OpenAI specifically
  • Your understanding of OpenAI’s mission and value proposition
  • What you’re looking for in your next role

Critical tip: Avoid revealing your salary expectations or disclosing where you are with other companies. Let the company make the first offer to maintain negotiating power.

Your recruiter will also outline what to expect in subsequent rounds, which can vary significantly based on your role and team.

Step 2: First Technical Phone Screen (1 Hour)

This round is conducted in CoderPad and focuses on algorithms and data structures. However, there’s a crucial distinction: OpenAI’s questions are more practical than typical LeetCode problems. You won’t see abstract string manipulation puzzles. Instead, expect problems that reflect real work scenarios you might encounter at the company.

The interviewers assess your ability to write code that is both performant now and flexible enough to scale and adapt in the future. You can choose your preferred programming language, and questions will be tailored accordingly.

Step 3: Second Technical Screen or Assessment (Format Varies)

This is where the process becomes highly variable. Depending on your role, you might encounter:

  • Another technical phone screen
  • An asynchronous coding assessment (potentially on HackerRank)
  • A take-home project
  • An architecture interview (especially for senior back-end engineers)

This round tends to be more domain-specific than the first technical screen, diving deeper into the particular skills needed for your target role.

Step 4: The Onsite (4-6 Hours)

The onsite typically consists of five distinct interviews:

Behavioral Interview with Senior Management (45 minutes)
This phone call with a high-level manager can be surprisingly interesting. While you’ll face standard behavioral questions, interviewers often dive deep into specific aspects of your resume that catch their attention. Be prepared for probing questions and ensure you’ve thought through your career decisions and experiences thoroughly.

Technical Presentation (45 minutes)
You’ll present a project you’ve worked on to a senior manager. While slides aren’t explicitly required, preparing them is strongly recommended. Be ready to discuss:

  • Technical implementation details
  • Business impact and metrics
  • Your specific contributions versus team contributions
  • Technical tradeoffs and decision-making processes
  • Team dynamics and collaboration challenges

Coding Interview (1 hour)
You can choose between your own IDE with screen-share or CoderPad. This interview maintains the practical focus of earlier coding rounds, emphasizing real-world problems over algorithmic puzzles. The questions are language-agnostic, and you’ll select your preferred language upfront.

System Design (1 hour)
Conducted using Excalidraw, this interview assesses your ability to architect large-scale systems. You might be asked to design familiar systems like Yelp, Twitter, or a notifications service.

Important warning: If you mention specific technologies, be prepared to defend your choices in detail. Interviewers probe deeply into the pros and cons of any tools you reference. Some candidates have even been asked to code their solution after designing it.

Team Collaboration Interview (30 minutes)
This second behavioral interview focuses specifically on your ability to work with others. Expect questions about:

  • Cross-functional collaboration experiences
  • Conflict resolution between teams or roles
  • Navigating competing ideas within your team
  • Your approach to building consensus

Technical Topics to Master

OpenAI-Specific Topics

Based on interviews with current and former engineers, certain technical areas appear more frequently at OpenAI than at other companies:

  • Time-based data structures: Understanding how to efficiently manage temporal data
  • Versioned data stores: Working with systems that maintain historical states
  • Coroutines and concurrency: Deep knowledge of multithreading and asynchronous programming in your chosen language
  • Object-oriented programming concepts: Abstract classes, iterators, inheritance patterns, and design principles

Standard Technical Topics

You’ll also encounter common interview topics found at other top-tier companies:

  • Algorithm design and optimization
  • Data structures and their appropriate use cases
  • System scalability and reliability patterns
  • Database design and query optimization
  • API design and RESTful principles

Essential Preparation Tips

1. Take Recruiter Guidance Seriously

Your recruiter will provide specific preparation tips before certain rounds. Don’t dismiss these as generic advice—OpenAI’s recruiters typically offer targeted guidance based on your specific interviewers and the team you’re targeting.

2. Study OpenAI’s Mission and Ethics

Read OpenAI’s blog, particularly articles discussing AI ethics and safety. The company genuinely cares about these topics and wants to ensure candidates have thought deeply about the implications of their work. This isn’t just box-checking—expect substantive discussions about AI safety, alignment, and responsible development.

3. Prepare Real-World Examples

Since OpenAI’s questions are practical rather than theoretical, your preparation should mirror real work scenarios. Focus on problems you’ve actually solved rather than memorizing algorithm solutions.

4. Practice System Design with Depth

For system design rounds, don’t just practice drawing boxes and arrows. Be prepared for interviewers to drill into any component of your design. If you mention Redis, know its internals. If you propose Kafka, understand exactly how partitioning and replication work.

5. Be Ready for Flexibility

You might apply for one role but be steered toward another as the process unfolds. Your interviewers may come from multiple teams. Embrace this flexibility rather than resisting it—OpenAI is trying to find the best mutual fit.

6. Create Presentation Slides

Even though they’re not required for the technical presentation, preparing slides demonstrates professionalism and helps structure your thoughts. Your presentation will be more polished and easier to follow.

The Hidden Challenge: Communication and Organization

Perhaps the most unexpected challenge candidates face isn’t technical difficulty—it’s navigating OpenAI’s relatively disorganized hiring process. Expect periods of silence and potential scheduling confusion. Stay proactive in following up with your recruiter, and don’t hesitate to apply gentle pressure if you have other time-sensitive opportunities.

What OpenAI Really Values

Beyond technical competency, OpenAI looks for engineers who can:

  • Think practically: Write code that solves real problems efficiently
  • Scale solutions: Design systems that adapt and grow
  • Collaborate effectively: Work across teams and handle conflict constructively
  • Consider implications: Think through the ethical dimensions of AI development
  • Communicate clearly: Explain technical decisions and tradeoffs to diverse audiences

Final Thoughts

Interviewing at OpenAI is a unique experience that combines rigorous technical assessment with philosophical depth about AI’s role in society. The process may feel chaotic, but it’s designed to be flexible enough to find the right role-team fit for each candidate.

The key to success isn’t just grinding LeetCode or memorizing system design patterns. It’s about demonstrating that you can solve real problems, think deeply about your technical choices, collaborate effectively with others, and contribute meaningfully to OpenAI’s mission of ensuring artificial intelligence benefits humanity.

Come prepared to showcase not just your technical skills, but your ability to think critically about the work itself and its broader implications. That’s what will ultimately set you apart in the OpenAI interview process.

I helped prepare our senior engineers for OpenAI interviews. Key insights: 1) They ask about scaling challenges specific to AI workloads - not generic system design. 2) Mission alignment isn’t just ‘why OpenAI?’ - they want you to identify specific technical challenges in responsible AI deployment. 3) For leadership roles, expect questions about building teams around novel AI capabilities. Sample: ‘How would you organize a team to build the next generation of agentic systems?’ They want to see both technical depth AND understanding of AI’s societal impact.

UX Engineering interview experience (June 2025): Coding question was implementing an autocomplete system with ranking/scoring (think ChatGPT’s suggestion system). System design: ‘Design the user interface for a new AI agent that can browse the web and take actions.’ They cared a lot about how to make AI interactions intuitive and safe for users. Behavioral focus was on ‘How do you balance AI capabilities with user control?’ Preparation tip: understand their product deeply - they asked detailed questions about ChatGPT’s UI decisions and reasoning.

Product Manager interview (September 2025): They asked me to ‘Design a feature that helps users detect AI-generated content in their workflows.’ Had to consider false positive rates, user education, and integration with existing products. Behavioral: ‘How would you prioritize conflicting safety requirements vs user experience requests?’ Also got: ‘Walk through how you’d launch a new AI capability to 100M users safely.’ They really care about responsible product development and gradual rollouts.

Finance interview here (August 2025): Technical question was surprisingly deep - ‘Model the GPU compute costs for serving ChatGPT at current scale, including peak load scenarios.’ Had to estimate token generation costs, infrastructure scaling, and margin analysis. Behavioral: ‘How would you structure pricing for a new AI capability that has uncertain demand?’ They wanted me to think about both unit economics and customer psychology. Also asked about ethical considerations in AI pricing models.

Mobile Engineering interview (July 2025): Coding question was implementing a smart text prediction system with offline capabilities (think iOS QuickType but for AI responses). System design: ‘How would you architect the ChatGPT mobile app to handle intermittent connectivity while maintaining conversation context?’ Had to design local caching, sync strategies, and conflict resolution. They asked detailed questions about iOS/Android AI framework integrations and on-device model optimization.

More ML questions from colleagues’ interviews: ‘Compute the KL divergence between two given distributions and explain when you’d use this in practice.’ ‘If a classifier has 100% accuracy on training data, what can you say about the loss function bounds?’ ‘Design an experiment to measure and reduce hallucinations in code generation models.’ Also: ‘How would you implement Constitutional AI from scratch?’ They expect you to know recent papers, especially around alignment and safety research.

More security-specific questions from recent interviews: ‘Design a system to detect coordinated inauthentic behavior in API usage patterns.’ ‘How would you secure a multi-modal AI system that processes images, text, and code?’ ‘Threat model a scenario where an adversary tries to extract training data from a deployed model.’ They also asked: ‘How would you implement differential privacy for model training while maintaining performance?’ Security at OpenAI is about AI-specific threats, not just traditional infra security.

Leadership interview questions (Director+ level): ‘How would you organize a 50-person team to build the next generation of multimodal AI systems?’ ‘Describe how you’d balance research exploration vs product delivery in a fast-moving AI team.’ ‘How do you ensure responsible AI development practices across multiple engineering teams?’ Also got asked about scaling challenges: ‘What are the key bottlenecks you’d expect when going from 1M to 1B users?’ They want leaders who understand both the technical and ethical dimensions of AI at scale.

Great additions everyone! A few more patterns I’ve noticed from our interview prep sessions: 1) They often ask follow-up questions like ‘How would this change if we had 10x more users/data/compute?’ 2) Expect questions about edge cases and failure modes - ‘What happens when your system fails? How do you detect and recover?’ 3) They love asking about trade-offs: ‘Would you optimize for latency, accuracy, or cost? Why?’ 4) Recent trend: questions about AI agent capabilities - ‘How would you design a system where AI agents collaborate on complex tasks?’ Keep the experiences coming! :rocket:

Research Scientist deep-dive questions from recent interviews: ‘Why does layer normalization work better than batch norm in transformers?’ ‘Explain the mathematical intuition behind attention mechanisms and derive the complexity.’ ‘How would you debug a model that’s overfitting - walk through your systematic approach.’ Also got: ‘Given two probability distributions P and Q, compute their KL divergence and explain 3 real-world scenarios where you’d use this metric.’ They expect you to derive formulas on the spot, not just memorize them.

More coding questions that aren’t typical LeetCode: ‘Implement an in-memory SQL-like database that supports INSERT and SELECT with WHERE clauses.’ Had to handle indexing, query optimization, and memory management. Another one: ‘Design and implement a rate limiter that can handle 1M requests per second with configurable policies.’ They want production-ready code that can scale, not just algorithms that work. Code quality, error handling, and testing are huge focuses.

System design deep-dive: ‘Design a distributed training system for models with 100B+ parameters.’ Had to cover data parallelism, model parallelism, gradient synchronization, fault tolerance, and checkpointing strategies. Follow-up: ‘How would you monitor and debug training failures at this scale?’ Also: ‘Design a system to deploy and monitor a large language model in production’ - covering inference optimization, load balancing, A/B testing infrastructure, and cost optimization. Very infrastructure-heavy focus.

ML Debugging interview style (similar to DeepMind): They gave me a PyTorch neural network implementation with 5-6 subtle bugs and asked me to find and fix them all within 45 minutes. Then: ‘Add batch normalization to this transformer implementation and explain your design choices.’ The bugs were things like incorrect tensor shapes, wrong loss function usage, memory leaks, and gradient computation errors. You need to be able to debug neural networks like a compiler expert.

Applied AI Engineer questions: ‘Design a user-facing product powered by GPT-4 that can handle 10M daily active users.’ Had to consider prompt engineering, response caching, cost optimization, and user safety. Coding: ‘Implement a context-aware autocomplete system that learns from user behavior.’ System design: ‘How would you build a notification system that adapts its messaging strategy based on user engagement patterns?’ They want you to think like a product engineer, not just a backend developer.

Advanced behavioral/strategic questions: ‘OpenAI just discovered that a competitor has achieved similar capabilities to GPT-4. How would you adapt our product strategy?’ ‘A regulatory body wants to audit our training data and model weights. Walk through your approach to compliance while protecting IP.’ ‘How would you design experiments to measure the societal impact of deploying a new AI capability?’ These aren’t just ‘tell me about a time’ questions - they want strategic thinking about AI governance and policy.

Senior/Staff Engineer questions: ‘Design the infrastructure to train GPT-5 assuming it needs 10x more compute than GPT-4.’ Cover hardware requirements, distributed training architecture, data pipeline design, and cost optimization. ‘How would you migrate ChatGPT from its current architecture to support multimodal inputs without downtime?’ Also: ‘Design a system where multiple AI agents collaborate to complete complex software development tasks.’ They expect you to think at massive scale with real constraints.