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
Backend Engineer
•
System Design
•
hard
Design the OpenAI API rate limiting system. It needs to enforce limits on requests per minute (RPM) and tokens per minute (TPM) across millions of users globally with minimal latency.
#Distributed Systems
#Redis
#Latency Optimization
Backend Engineer
•
System Design
•
hard
Design a system for streaming LLM responses to millions of concurrent users. How do you handle connection drops and ensure tokens are delivered in order?
#Server-Sent Events (SSE)
#WebSockets
#Load Balancing
#Connection Management
Backend Engineer
•
System Design
•
hard
Design a webhook delivery system for asynchronous API requests (e.g., batch processing of millions of prompts).
#Message Queues
#Retry Mechanisms
#Idempotency
#Rate Limiting
Backend Engineer
•
System Design
•
hard
Design a GPU resource scheduler for batch processing inference jobs. Some jobs have higher priority, and GPUs have varying memory capacities.
#Resource Allocation
#Scheduling Algorithms
#Distributed Systems
Backend Engineer
•
System Design
•
medium
Design ChatGPT's conversation history storage system. It must support fast retrieval of recent chats, full-text search, and handle massive write volume.
#Databases
#Sharding
#Search Engines
Backend Engineer
•
System Design
•
hard
Design a system to detect and block malicious prompts (jailbreaks) in real-time before they reach the LLM.
#Security
#Stream Processing
#Machine Learning Infrastructure
Backend Engineer
•
System Design
•
medium
Design a scalable distributed cache for LLM prompt/response pairs to save compute on identical queries.
#Caching
#Hashing
#Consistency
Backend Engineer
•
System Design
•
hard
Design an ingestion pipeline for training data that continuously processes petabytes of text from the web.
#Data Engineering
#Kafka
#MapReduce
#Storage
Backend Engineer
•
System Design
•
medium
Design a real-time monitoring and alerting system for model inference latency across multiple geographic regions.
#Observability
#Time-Series Databases
#Data Aggregation
Backend Engineer
•
System Design
•
hard
Design a vector database for storing and querying billions of embeddings generated by our models.
#Vector Search
#ANN Algorithms
#Sharding
#Databases
Difficulty Radar
Based on recent AI-sourced data.
Meet Your Interviewers
The "Standard" Interviewer
Senior EngineerFocuses on core competencies, system constraints, and clear communication.
SimulateUnwritten Rules
Think Out Loud
Always explain your thought process before writing code or drawing architecture.