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
Machine Learning Engineer
•
Technical
•
medium
Derive the exact GPU memory requirements for training a 7 Billion parameter model using the Adam optimizer in mixed precision (fp16/bf16).
#Hardware
#Optimization
#Memory Management
Machine Learning Engineer
•
Technical
•
hard
Explain how FlashAttention works. Why does it reduce memory bandwidth, and how does it achieve exact attention mathematically?
#Transformers
#CUDA
#Hardware Optimization
Machine Learning Engineer
•
Technical
•
hard
What are the mathematical and practical differences between Proximal Policy Optimization (PPO) and Direct Preference Optimization (DPO) in the context of RLHF?
#Reinforcement Learning
#RLHF
#Loss Functions
Machine Learning Engineer
•
Technical
•
hard
Explain Rotary Positional Embeddings (RoPE). Why are they preferred over absolute positional embeddings in modern LLMs?
#Transformers
#Mathematics
#NLP
Machine Learning Engineer
•
Technical
•
medium
What is the difference between Tensor Parallelism and Pipeline Parallelism? When would you use each, and what are their respective communication bottlenecks?
#Distributed Systems
#Parallel Computing
Machine Learning Engineer
•
Technical
•
medium
Explain the difference between Layer Normalization and RMSNorm. Why has the industry largely shifted to RMSNorm for LLMs?
#Deep Learning
#Optimization
Machine Learning Engineer
•
Technical
•
medium
How do you handle catastrophic forgetting when fine-tuning a pre-trained LLM on a highly specific, narrow domain?
#Fine-tuning
#Transfer Learning
Machine Learning Engineer
•
Technical
•
easy
Explain the vanishing gradient problem. How do architectural innovations like Residual Connections (ResNets) and Transformers mitigate this issue?
#Deep Learning Basics
#Architecture
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.