OpenAI
Leading AI research laboratory developing state-of-the-art foundation models like GPT-4.
5 Rounds
~21 Days
Very Hard
The Interview Loop
Recruiter Screen (30 min)
Standard fit check, behavioral questions, and resume overview.
Technical Loop (3-4 Rounds)
Deep dive into domain knowledge, coding, and system design.
Interview Question Bank
Full Stack Engineer
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Behavioral
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medium
Tell me about a time you had to ship a feature under extreme time pressure. What technical corners did you cut, and how did you manage the resulting technical debt?
#Delivery
#Technical Debt
#Prioritization
Full Stack Engineer
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Behavioral
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medium
Describe a situation where you disagreed with a product manager or AI researcher about the technical direction of a feature. How did you resolve it?
#Communication
#Conflict Resolution
#Collaboration
Full Stack Engineer
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Behavioral
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medium
OpenAI moves incredibly fast. Tell me about a time you had to pivot your technical approach halfway through a project due to changing requirements or new model capabilities.
#Adaptability
#Agile
#Resilience
Full Stack Engineer
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Behavioral
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hard
Tell me about a complex production incident you debugged. What was the root cause, and what specific steps did you take to prevent it from happening again?
#Incident Management
#Debugging
#Post-mortems
Full Stack Engineer
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Behavioral
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hard
How do you balance the need for rapid iteration and shipping features quickly with the necessity of maintaining rigorous AI safety, privacy, and security standards?
#Ethics
#Security
#Productivity
Full Stack Engineer
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Behavioral
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medium
Describe a time you took ownership of a poorly defined problem or ambiguous feature request and drove it to successful completion.
#Ownership
#Ambiguity
#Execution
Full Stack Engineer
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Behavioral
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easy
Tell me about a time you had to learn a completely new technology, framework, or domain on the fly to deliver a critical project.
#Learning
#Adaptability
#Growth Mindset
Full Stack Engineer
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Coding
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medium
Implement a React component that consumes a Server-Sent Events (SSE) endpoint to display a streaming chat response, similar to ChatGPT.
#React
#SSE
#Streaming
#State Management
Full Stack Engineer
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Coding
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hard
Write a rate limiter in Python using Redis to handle OpenAI API tier limits, specifically enforcing both tokens per minute (TPM) and requests per minute (RPM).
#Python
#Redis
#Rate Limiting
#Concurrency
Full Stack Engineer
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Coding
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medium
Implement an LRU cache with a time-to-live (TTL) feature. If an item expires, it should not be returned, and it should be evicted.
#Data Structures
#Hash Map
#Linked List
Full Stack Engineer
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Coding
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medium
Design a function to merge overlapping text highlights in a document. Given an array of intervals [start, end], return an array of non-overlapping intervals.
#Arrays
#Sorting
#Intervals
Full Stack Engineer
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Coding
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medium
Write a Python script using asyncio to fetch data from multiple LLM endpoints concurrently, aggregate the results, and return early if any request exceeds a 2-second timeout.
#Python
#asyncio
#Concurrency
#API Integration
Full Stack Engineer
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Coding
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easy
Create a custom React hook `useDebounce` and implement it within an autocomplete search input for querying a prompt library.
#React
#Hooks
#Performance
Full Stack Engineer
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Coding
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easy
Given a raw text string representing a conversation, parse it into a structured JSON format of roles (system, user, assistant) and content blocks.
#String Manipulation
#Parsing
#Regex
Full Stack Engineer
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Coding
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hard
Implement a simplified Byte Pair Encoding (BPE) token counting algorithm that calculates the number of tokens in a given string based on a provided vocabulary dictionary.
#Strings
#Greedy Algorithms
#NLP
Full Stack Engineer
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Coding
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medium
Write a function to traverse a DOM tree and extract all visible text, simulating how a web scraper plugin might extract context for an LLM.
#DOM Manipulation
#Recursion
#Trees
Full Stack Engineer
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Coding
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medium
Implement a concurrent task runner in TypeScript that processes an array of async tasks but limits the maximum number of active promises to a given concurrency limit.
#TypeScript
#Promises
#Concurrency
Full Stack Engineer
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System Design
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hard
Design the architecture for ChatGPT's web interface, focusing on real-time streaming, chat history persistence, and state management across multiple devices.
#Architecture
#Streaming
#State Management
#Databases
Full Stack Engineer
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System Design
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medium
Design a system to handle webhooks for OpenAI API fine-tuning jobs, ensuring at-least-once delivery and handling downstream customer endpoint failures.
#Webhooks
#Message Queues
#Retry Logic
#Distributed Systems
Full Stack Engineer
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System Design
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hard
How would you design a scalable prompt evaluation platform where enterprise users can run A/B tests on different LLM prompts across millions of dataset rows?
#Batch Processing
#Scalability
#Data Pipelines
#Analytics
Full Stack Engineer
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System Design
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hard
Design an API gateway that routes requests to different model endpoints (e.g., GPT-3.5, GPT-4) based on load, availability, and user subscription tier.
#API Gateway
#Load Balancing
#Routing
#High Availability
Full Stack Engineer
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System Design
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medium
Design the database schema and backend architecture for storing and retrieving user chat histories with minimal latency, considering users might have thousands of long conversations.
#Database Design
#Indexing
#NoSQL
#Caching
Full Stack Engineer
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System Design
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hard
Design a real-time collaborative prompt playground where multiple users can edit a prompt simultaneously and see model outputs, similar to Google Docs.
#WebSockets
#CRDTs
#Operational Transformation
#Real-time
Full Stack Engineer
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System Design
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hard
How would you architect a system to securely store, process, and manage user-uploaded files for the Advanced Data Analysis (Code Interpreter) feature?
#Security
#Storage
#Sandboxing
#Microservices
Full Stack Engineer
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System Design
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hard
Design a distributed rate limiting system for the OpenAI API that enforces both Requests Per Minute (RPM) and Tokens Per Minute (TPM) globally across multiple data centers.
#Distributed Systems
#Rate Limiting
#Redis
#Eventual Consistency
Full Stack Engineer
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System Design
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medium
Design a logging and monitoring pipeline to track API latency, error rates, and token usage per customer in real-time.
#Observability
#Data Pipelines
#Metrics
#Elasticsearch/Prometheus
Full Stack Engineer
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System Design
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hard
Architect a plugin execution engine that safely calls third-party APIs based on LLM outputs while preventing Server-Side Request Forgery (SSRF) and timing attacks.
#Security
#API Integration
#Network Architecture
Full Stack Engineer
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Technical
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medium
Explain the differences between WebSockets, Server-Sent Events (SSE), and long polling. Why did OpenAI choose SSE for streaming ChatGPT responses?
#Networking
#Protocols
#Streaming
Full Stack Engineer
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Technical
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hard
How do you handle React state updates when receiving high-frequency streaming data (e.g., 50 chunks per second) without causing UI freezing or performance degradation?
#React
#Performance
#Rendering
Full Stack Engineer
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Technical
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medium
Describe how you would implement optimistic UI updates for a chat application where the backend response might take several seconds to begin.
#UX
#State Management
#API Integration
Full Stack Engineer
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Technical
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medium
How would you optimize a Python backend service that is heavily I/O bound due to waiting for model inference from GPU clusters?
#Python
#Performance
#Asynchronous Programming
Full Stack Engineer
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Technical
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medium
What are the security implications of rendering Markdown and HTML generated by an LLM, and how do you mitigate Cross-Site Scripting (XSS) attacks?
#Frontend Security
#XSS
#Sanitization
Full Stack Engineer
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Technical
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medium
Explain how you would manage database migrations in a high-traffic environment with zero downtime, specifically when adding a new column to a table with billions of rows.
#Database Administration
#Zero Downtime
#Migrations
Full Stack Engineer
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Technical
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medium
How does Python's Global Interpreter Lock (GIL) affect the performance of a multi-threaded web server, and how would you architect around it for a CPU-intensive task?
#Python
#Concurrency
#Multiprocessing
Full Stack Engineer
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Technical
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hard
Describe your approach to testing a non-deterministic system, such as a UI component that relies on LLM-generated content which changes every time.
#QA
#Mocking
#E2E Testing
Difficulty Radar
Based on recent AI-sourced data.
Meet Your Interviewers
The "Standard" Interviewer
Senior EngineerFocuses on core competencies, system constraints, and clear communication.
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Think Out Loud
Always explain your thought process before writing code or drawing architecture.