OpenAI Coding Interview Questions

You are given an M×N 2D grid representing a field of plants. Each cell is one of: 'X' (infected), '.' (healthy/susceptible), or…

Implement a GPU credit management system with the following methods: 1. add_credit(grant_id, amount, start_timestamp, expiration_duration_or_expiry_timestamp) — Add a credit grant with a…

Implement a durable key-value store class with the following API: - put(key: str, value: str) / set(key, value) — insert or overwrite…

Implement an in-memory SQL-like database from scratch with no external frameworks. You are given (or must design) a DB class and must…

You are given a toy programming language with the following grammar: Primitives: char, int, float (lowercase strings) Generics: Uppercase letter + number,…

You are given an n-ary tree where each node represents a machine in a distributed cluster. Each node knows its own ID,…

Design and implement a resumable iterator — an iterator that supports pausing and resuming from a saved checkpoint. The iterator must expose…

Given a human-annotated dataset (text or image, e.g., CIFAR) that has been read into a Python environment (typically a Jupyter notebook with…

Implement a multi-part IPv4 iterator system in Python using the standard iterator protocol (__init__, __iter__, __next__). The problem is revealed one part…

Implement a SocialNetwork class that models a directed follow graph with snapshot (versioning) support. The system must support: Part 1 – Core…

Design and implement a turn-based battle engine for two teams of monsters. Each team has an ordered list of monsters; each monster…

You are given an existing, messy codebase (approximately 100–1500 lines, depending on variant) implementing a chat/bot message processing system. The code handles…

Design and implement a memory allocator class. Initialize with a total memory size N (e.g., N=1000 bytes representing indices 0 to N-1,…

A 60-minute ML coding interview in which the candidate must implement a simple numerical routine involving arrays and basic math operations using…

Given a transformer model (typically after a debugging/bug-fixing exercise on the same codebase), implement KV cache to optimize autoregressive decoding/generation. A skeleton…

You are given a sorted list of software dependency version strings in 'major.minor.patch' format (e.g., ['103.003.02', '103.003.03', '203.003.02', '1.1.1']). Each version either…

A machine learning coding interview delivered as a Jupyter notebook or Python/PyTorch file (often 400+ lines with a skeleton to complete), covering:…

Given a vector of logits (raw unnormalized scores), implement Shannon entropy of the corresponding softmax distribution. The entropy is H = -Σ…

A multi-part SQL coding problem. Based on reports, it involves implementing database-like query operations in code, covering: (1) GET and SET operations,…

Design and implement a text editor data structure that supports four progressively complex parts: Part 1 — Basic Text Buffer: Implement a…

You are given a buggy Python rate limiter implementation for a ChatGPT-like API service. The rate limiter is integrated into a web…

You are working on a Fraud / Trust & Safety team. Investigate the following scenario: the same IP address has been used…

Implement a Spreadsheet class with two methods: setCell(key, value) and getCell(key). Cells can hold either literal numeric values (e.g., '1', '2') or…

Build a rating card component in Kotlin Compose with rating and comment fields (both required before submission). Display success message after submit.…

Construct a scheduler for t tasks, m models, and h human labelers returning (task, model, human) tuples. Constraints: each human assigned ≥k…

Parse instrument name and beat sequence (binary-like notation where '1 0' = half note, '1 1' = two quarter notes),…

Implement three functions for a grant-based balance system: create_grant(id, amount, timestamp, expiretime), subtract(amount, timestamp), get_balance(timestamp). Grants expire based on…

OpenAI phone screen reportedly includes bitwise operations question. HR confirmed it is an algorithms problem…

Implement a 'cd' command that handles relative paths with special cases ('../A/B/', './A/', '../A/B/../', etc.). Write a cd() method that simplifies…

A coding challenge requiring knowledge of reinforcement learning, specifically Group Relative Policy Optimization (GRPO), and PyTorch. Task involves debugging and improving an…

Schedule annotators (A) to label questions (Q) with multiple models (M). Constraints: (1) each (model, question) pair assigned evenly; (2) for each…

Given versions in {major}.{minor}.{patch} format, find the earliest version supporting a feature using API calls optimized below linear complexity. Requires identifying that…

Part 1 (known problem): Given multiple shards with overlapping thresholds, output rebalanced shards minimizing data movement; solved using mini heap to maintain…

Build a React component mimicking the ChatGPT UI (input box, message flow, loading states, streaming response handling).…

Similar to LeetCode 289. Approximately 5 sub-questions total. Requires careful attention to clarifying questions as some standard assumptions may change during the…

Given an N×M grid starting from (0,p), reach bottom row via moves to (i+1,j-1), (i+1,j), (i+1,j+1), or special jump (i+2,j) up to…

In an m×n grid with '.', '#', and '' cells, find the shortest path visiting all ''…

Starting from a given number, at each step you can add any element from an array and take modulo. Find minimum steps…