OpenAI Machine Learning Engineer Interview Experience — Transformer Bug Hunt with KV Cache from Scratch and a Five-Part Plant Infection Problem

OpenAI·Machine Learning Engineer·Sep 2026
Technical Screenmedium

Hi,

I am preparing for OpenAI's ML coding interview and have summarized the ML coding questions mentioned in the OpenAI/Anthropic interview rounds I have given so far.

Anthropic

  1. Research Fundamentals Round: It was related to implementing an ML algo and discussing various research/mathematical aspects around it.

OpenAI

  1. ML Coding (Transformer Debugging): Debugging 4-5 implanted bugs in the transformer code and implementing KV cache from scratch.
  2. Coding (Plant Infection): 5 part question on plant infection.

Wishing everyone good luck!

Published

Curated and edited by PracHub

Practice the questions from this interview

Debug a Transformer Implementation and Implement a KV Cache for Decoding

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Interview at a glance

Company
OpenAI
Role
Machine Learning Engineer
Rounds
Technical Screen
Difficulty
medium
Interview date
Sep 2026
Questions from this interview
1 question

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